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Sync with Linus #23

Merged
merged 354 commits into from
Jan 20, 2015
Merged

Sync with Linus #23

merged 354 commits into from
Jan 20, 2015

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dabrace
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@dabrace dabrace commented Jan 20, 2015

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martinkpetersen and others added 30 commits January 8, 2015 10:35
… TRIM

As defined, the DRAT (Deterministic Read After Trim) and RZAT (Return
Zero After Trim) flags in the ATA Command Set are unreliable in the
sense that they only define what happens if the device successfully
executed the DSM TRIM command. TRIM is only advisory, however, and the
device is free to silently ignore all or parts of the request.

In practice this renders the DRAT and RZAT flags completely useless and
because the results are unpredictable we decided to disable discard in
MD for 3.18 to avoid the risk of data corruption.

Hardware vendors in the real world obviously need better guarantees than
what the standards bodies provide. Unfortuntely those guarantees are
encoded in product requirements documents rather than somewhere we can
key off of them programatically. So we are compelled to disabling
discard_zeroes_data for all devices unless we explicitly have data to
support whitelisting them.

This patch whitelists SSDs from a few of the main vendors. None of the
whitelists are based on written guarantees. They are purely based on
empirical evidence collected from internal and external users that have
tested or qualified these drives in RAID deployments.

The whitelist is only meant as a starting point and is by no means
comprehensive:

   - All intel SSD models except for 510
   - Micron M5?0/M600
   - Samsung SSDs
   - Seagate SSDs

Signed-off-by: Martin K. Petersen <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
When the queue is set to dying, wake up tasks that are waiting on frozen
queue so they realize it is dying and abandon their request.

Signed-off-by: Keith Busch <[email protected]>

Modified by me to add a code comment on the need for the wakeup.

Signed-off-by: Jens Axboe <[email protected]>
Drivers can iterate over all allocated request tags, but their callback
needs a way to know if the driver started the request in the first place.

Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Kicking requeued requests will start h/w queues in a work_queue, which
may alter the driver's requested state to temporarily stop them. This
patch exports a method to cancel the q->requeue_work so a driver can be
assured stopped h/w queues won't be started up before it is ready.

Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Adds a helper function a driver can use to abort requeued requests in
case any are pending when h/w queues are being removed.

Signed-off-by: Jens Axboe <[email protected]>
Some types of requests may be started that are not gauranteed to ever
complete. This adds a request flag that a driver can use so mark the
request as such.

Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Requests that haven't been started prior to a queue dying can be ended
in error without waiting for them to start and time out.

Signed-off-by: Keith Busch <[email protected]>

Added code comment to explain why this is done.

Signed-off-by: Jens Axboe <[email protected]>
Once the nvme callback is set for a request, the driver can start it
and make it available for timeout handling. For timed out commands on a
device that is not initialized, this fixes potential deadlocks that can
occur on startup and shutdown when a device is unresponsive since they
can now be cancelled.

Asynchronous requests do not have any expected timeout, so these are
using the new "REQ_NO_TIMEOUT" request flags.

Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Since there is no gendisk associated with the admin queue, the driver
needs to hold a reference to it until all open references to the
controller are closed.

This also combines queue cleanup with freeing the tag set since these
should not be separate.

Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This protects admin queue access on shutdown. When the controller is
disabled, the queue is frozen to prevent new entry, and unfrozen on
resume, and fixes cq_vector signedness to not suspend a queue twice.

Since unfreezing the queue makes it available for commands, it requires
the queue be initialized, so this moves this part after that.

Special handling is done when the device is unresponsive during
shutdown. This can be optimized to not require subsequent commands to
timeout, but saving that fix for later.

This patch also removes the kill signals in this path that were left-over
artifacts from the blk-mq conversion and no longer necessary.

Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Aborts all requeued commands prior to killing the request_queue. For
commands that time out on a dying request queue, set the "Do Not Retry"
bit on the command status so the command cannot be requeued. Finanally, if
the driver is requested to abort a command it did not start, do nothing.

Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This freezes and stops all the queues on device shutdown and restarts
them on resume. This fixes hotplug and reset issues when the controller
is actively being used.

Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
The queues and device need to be locked when messing with them.

Signed-off-by: Keith Busch <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
DP PHY now require pmu-system-controller to handle PMU register
to control PHY's power isolation. Adding the same to dp-phy
node.

Signed-off-by: Vivek Gautam <[email protected]>
Reviewed-by: Jingoo Han <[email protected]>
Tested-by: Javier Martinez Canillas <[email protected]>
Signed-off-by: Kukjin Kim <[email protected]>
This change allows the driver to recognize newer Elantech touchpads.

Cc: [email protected]
Signed-off-by: Yi ju Hong <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
When KBC is in active multiplexing mode the touchpad on this laptop does
not work.

Reported-by: Bilal Koc <[email protected]>
Cc: [email protected]
Signed-off-by: Dmitry Torokhov <[email protected]>
…/kernel/git/jic23/iio into staging-linus

Jonathan writes:

First round of IIO fixes for the 3.19 cycle.

* ad799x fix ad7991/ad7995/ad7999 setup as they do not have a configuration
  register to write to.  It is written during the convesion sequence. As
  such we don't want to write to it at other times.
* Fix iio_channel_read utility function to return to ensure it is apparent
  if the relevant element is not there. This avoids using a wrong value
  if some channels have the element and others do not.
…t/jkirsher/net

Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates 2015-01-06

This series contains fixes to i40e only.

Jesse provides a fix for when the driver was polling with interrupts
disabled the hardware would occasionally not write back descriptors.
His fix causes the driver to detect this situation and force an interrupt
to fire which will flush the stuck descriptor.

Anjali provides a couple of fixes, the first corrects an issue where
the receive port checksum error counter was incrementing incorrectly with
UDP encapsulated tunneled traffic.  The second fix resolves an issue where
the driver was examining the outer protocol layer to set the inner protocol
layer checksum offload.  In the case of TCP over IPv6 over an IPv4 based
VXLAN, the inner checksum offloads would be set to look for IPv4/UDP
instead of IPv6/TCP, so fixed the issue so that the driver will look at
the proper layer for encapsulation offload settings.

v2: fixed a bug in patch 01 of the series, where the interrupt rate impacted
    4 port workloads by reducing throughput.
====================

Signed-off-by: David S. Miller <[email protected]>
FDR register of R-Car set in fdr_value can have the original settings.
This sets the value that is suitable for each SoCs to fdr_value of R8A777x
and R8A779x.

Signed-off-by: Nobuhiro Iwamatsu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
TRSCER register is configured differently by SoCs. TRSCER of R-Car Gen2 is
RINT8 bit only valid, other bits are reserved bits. This removes access to
TRSCER register reserve bit by adding variable trscer_err_mask to
sh_eth_cpu_data structure, set the register information to each SoCs.

Signed-off-by: Nobuhiro Iwamatsu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
This patch initialises the fep->netdev pointer. This pointer was not
initialised at all, but is used in fec_enet_timeout_work and in some
error paths.

Signed-off-by: Hubert Feurstein <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Currently the LOAD NEGATIVE (lnr) instruction is used for ALU_NEG. This
instruction always loads the negative value. Therefore, if A is already
negative, it remains unchanged. To fix this use LOAD COMPLEMENT (lcr)
instead.

Signed-off-by: Michael Holzheu <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
Currently the signed COMPARE (cr) instruction is used to compare "A"
with "X". This is not correct because "A" and "X" are both unsigned.
To fix this use the unsigned COMPARE LOGICAL (clr) instruction instead.

Signed-off-by: Michael Holzheu <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
Signed-off-by: Nilesh Javali <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
The blk-mq ->queue_rq method is always called from process context,
but might have preemption disabled.  This means we still always
have to use GFP_ATOMIC for memory allocations, and thus need to
revert part of commit 3c356bd ("scsi: stop passing a gfp_mask
argument down the command setup path").

Signed-off-by: Christoph Hellwig <[email protected]>
Reported-by: Sasha Levin <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Tested-by: Alexei Starovoitov <[email protected]>
…git/kishon/linux-phy into usb-linus

Kishon writes:

misc fixes in PHY drivers
This reverts commit 14b4099

It moved platform_set_drvdata(pdev, ci) before hcd is created,
and the hcd will assign itself as ci controller's drvdata during
the hcd creation function (in usb_create_shared_hcd), so it
overwrites the real ci's drvdata which we want to use.

So, if the controller is at host mode, the system suspend
API will get the wrong struct ci_hdrc pointer, and cause the
oops.

Signed-off-by: Peter Chen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Solves xhci error cases with debug messages:
xhci_hcd 0000:00:14.0: Setup ERROR: setup context command for slot 1.
usb 1-6: hub failed to enable device, error -22

xhci will give a context state error if we try to set a slot in default
state to the same default state with a special address device command.

Turns out this happends in several cases:
- retry reading the device rescriptor in hub_port_init()
- usb_reset_device() is called for a slot in default state
- in resume path, usb_port_resume() calls hub_port_init()

The default state is usually reached from most states with a reset device
command without any context state errors, but using the address device
command with BSA bit set (block set address) only works from the enabled
state and will otherwise cause context error.

solve this by checking if we are already in the default state before issuing
a address device BSA=1 command.

Fixes: 48fc7db ("usb: xhci: change enumeration scheme to 'new scheme'")
Cc: <[email protected]> # v3.14+
Signed-off-by: Mathias Nyman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Commit c3ee9b7 (EHCI: improved logic for isochronous scheduling)
introduced the idea of using ehci->last_iso_frame as the origin (or
base) for the circular calculations involved in modifying the
isochronous schedule.  However, the new code it added used
ehci->last_iso_frame before the value was properly initialized.  This
patch rectifies the mistake by moving the initialization lines earlier
in iso_stream_schedule().

This fixes Bugzilla #72891.

Signed-off-by: Alan Stern <[email protected]>
Fixes: c3ee9b7
Reported-by: Joe Bryant <[email protected]>
Tested-by: Joe Bryant <[email protected]>
Tested-by: Martin Long <[email protected]>
CC: <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
The USB stack uses error code -ENOSPC to indicate that the periodic
schedule is too full, with insufficient bandwidth to accommodate a new
allocation.  It uses -EFBIG to indicate that an isochronous transfer
could not be linked into the schedule because it would exceed the
number of isochronous packets the host controller driver can handle
(generally because the new transfer would extend too far into the
future).

ehci-hcd uses the wrong error code at one point.  This patch fixes it,
along with a misleading comment and debugging message.

Signed-off-by: Alan Stern <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
…ernel/git/tj/libata

Pull libata fixes from Tejun Heo:

 - Bartlomiej will be co-maintaining PATA portion of libata.  git
   workflow will stay the same.

 - sata_sil24 wasn't happy with tag ordered submission.  An option to
   restore the old tag allocation behavior is implemented for sil24.

 - a very old race condition in PIO host state machine which can trigger
   BUG fixed.

 - other driver-specific changes

* 'for-3.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  libata: prevent HSM state change race between ISR and PIO
  libata: allow sata_sil24 to opt-out of tag ordered submission
  ata: pata_at91: depend on !ARCH_MULTIPLATFORM
  ahci: Remove Device ID for Intel Sunrise Point PCH
  ahci: Use dev_info() to inform about the lack of Device Sleep support
  libata: Whitelist SSDs that are known to properly return zeroes after TRIM
  sata_dwc_460ex: fix resource leak on error path
  ata: add MAINTAINERS entry for libata PATA drivers
  libata: clean up MAINTAINERS entries
  libata: export ata_get_cmd_descript()
  ahci_xgene: Fix the DMA state machine lockup for the ATA_CMD_PACKET PIO mode command.
  ahci_xgene: Fix the endianess issue in APM X-Gene SoC AHCI SATA controller driver.
dabrace added a commit that referenced this pull request Jan 20, 2015
@dabrace dabrace merged commit fc73c67 into dabrace:master Jan 20, 2015
dabrace pushed a commit that referenced this pull request Apr 17, 2015
One path in power_pmu_event_init() calls get_cpu_var(), but is
missing matching call to put_cpu_var(), which causes preemption
imbalance and crash in user-space:

  Page fault in user mode with in_atomic() = 1 mm = c000001fefa5a280
  NIP = 3fff9bf2cae0  MSR = 900000014280f032
  Oops: Weird page fault, sig: 11 [#23]
  SMP NR_CPUS=2048 NUMA PowerNV
  Modules linked in: <snip>
  CPU: 43 PID: 10285 Comm: a.out Tainted: G      D         4.0.0-rc5+ #1
  task: c000001fe82c9200 ti: c000001fe835c000 task.ti: c000001fe835c000
  NIP: 00003fff9bf2cae0 LR: 00003fff9bee4898 CTR: 00003fff9bf2cae0
  REGS: c000001fe835fea0 TRAP: 0401   Tainted: G      D          (4.0.0-rc5+)
  MSR: 900000014280f032 <SF,HV,VEC,VSX,EE,PR,FP,ME,IR,DR,RI>  CR: 22000028  XER: 00000000
  CFAR: 00003fff9bee4894 SOFTE: 1
   GPR00: 00003fff9bee494c 00003fffe01c2ee0 00003fff9c084410 0000000010020068
   GPR04: 0000000000000000 0000000000000002 0000000000000008 0000000000000001
   GPR08: 0000000000000001 00003fff9c074a30 00003fff9bf2cae0 00003fff9bf2cd70
   GPR12: 0000000052000022 00003fff9c10b700
  NIP [00003fff9bf2cae0] 0x3fff9bf2cae0
  LR [00003fff9bee4898] 0x3fff9bee4898
  Call Trace:
  ---[ end trace 5d3d952b5d4185d4 ]---

  BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:41
  in_atomic(): 1, irqs_disabled(): 0, pid: 10285, name: a.out
  INFO: lockdep is turned off.
  CPU: 43 PID: 10285 Comm: a.out Tainted: G      D         4.0.0-rc5+ #1
  Call Trace:
  [c000001fe835f990] [c00000000089c014] .dump_stack+0x98/0xd4 (unreliable)
  [c000001fe835fa10] [c0000000000e4138] .___might_sleep+0x1d8/0x2e0
  [c000001fe835faa0] [c000000000888da8] .down_read+0x38/0x110
  [c000001fe835fb30] [c0000000000bf2f4] .exit_signals+0x24/0x160
  [c000001fe835fbc0] [c0000000000abde0] .do_exit+0xd0/0xe70
  [c000001fe835fcb0] [c00000000001f4c4] .die+0x304/0x450
  [c000001fe835fd60] [c00000000088e1f4] .do_page_fault+0x2d4/0x900
  [c000001fe835fe30] [c000000000008664] handle_page_fault+0x10/0x30
  note: a.out[10285] exited with preempt_count 1

Reproducer:
  #include <stdio.h>
  #include <unistd.h>
  #include <syscall.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <linux/perf_event.h>
  #include <linux/hw_breakpoint.h>

  static struct perf_event_attr event = {
          .type = PERF_TYPE_RAW,
          .size = sizeof(struct perf_event_attr),
          .sample_type = PERF_SAMPLE_BRANCH_STACK,
          .branch_sample_type = PERF_SAMPLE_BRANCH_ANY_RETURN,
  };

  int main()
  {
          syscall(__NR_perf_event_open, &event, 0, -1, -1, 0);
  }

Signed-off-by: Jan Stancek <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
dabrace pushed a commit that referenced this pull request Aug 5, 2015
Nikolay has reported a hang when a memcg reclaim got stuck with the
following backtrace:

PID: 18308  TASK: ffff883d7c9b0a30  CPU: 1   COMMAND: "rsync"
  #0 __schedule at ffffffff815ab152
  #1 schedule at ffffffff815ab76e
  #2 schedule_timeout at ffffffff815ae5e5
  #3 io_schedule_timeout at ffffffff815aad6a
  #4 bit_wait_io at ffffffff815abfc6
  #5 __wait_on_bit at ffffffff815abda5
  #6 wait_on_page_bit at ffffffff8111fd4f
  #7 shrink_page_list at ffffffff81135445
  #8 shrink_inactive_list at ffffffff81135845
  #9 shrink_lruvec at ffffffff81135ead
 #10 shrink_zone at ffffffff811360c3
 #11 shrink_zones at ffffffff81136eff
 #12 do_try_to_free_pages at ffffffff8113712f
 #13 try_to_free_mem_cgroup_pages at ffffffff811372be
 #14 try_charge at ffffffff81189423
 #15 mem_cgroup_try_charge at ffffffff8118c6f5
 #16 __add_to_page_cache_locked at ffffffff8112137d
 #17 add_to_page_cache_lru at ffffffff81121618
 #18 pagecache_get_page at ffffffff8112170b
 #19 grow_dev_page at ffffffff811c8297
 #20 __getblk_slow at ffffffff811c91d6
 #21 __getblk_gfp at ffffffff811c92c1
 #22 ext4_ext_grow_indepth at ffffffff8124565c
 #23 ext4_ext_create_new_leaf at ffffffff81246ca8
 #24 ext4_ext_insert_extent at ffffffff81246f09
 #25 ext4_ext_map_blocks at ffffffff8124a848
 #26 ext4_map_blocks at ffffffff8121a5b7
 #27 mpage_map_one_extent at ffffffff8121b1fa
 #28 mpage_map_and_submit_extent at ffffffff8121f07b
 #29 ext4_writepages at ffffffff8121f6d5
 #30 do_writepages at ffffffff8112c490
 #31 __filemap_fdatawrite_range at ffffffff81120199
 #32 filemap_flush at ffffffff8112041c
 #33 ext4_alloc_da_blocks at ffffffff81219da1
 #34 ext4_rename at ffffffff81229b91
 #35 ext4_rename2 at ffffffff81229e32
 #36 vfs_rename at ffffffff811a08a5
 #37 SYSC_renameat2 at ffffffff811a3ffc
 #38 sys_renameat2 at ffffffff811a408e
 #39 sys_rename at ffffffff8119e51e
 #40 system_call_fastpath at ffffffff815afa89

Dave Chinner has properly pointed out that this is a deadlock in the
reclaim code because ext4 doesn't submit pages which are marked by
PG_writeback right away.

The heuristic was introduced by commit e62e384 ("memcg: prevent OOM
with too many dirty pages") and it was applied only when may_enter_fs
was specified.  The code has been changed by c3b94f4 ("memcg:
further prevent OOM with too many dirty pages") which has removed the
__GFP_FS restriction with a reasoning that we do not get into the fs
code.  But this is not sufficient apparently because the fs doesn't
necessarily submit pages marked PG_writeback for IO right away.

ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily
submit the bio.  Instead it tries to map more pages into the bio and
mpage_map_one_extent might trigger memcg charge which might end up
waiting on a page which is marked PG_writeback but hasn't been submitted
yet so we would end up waiting for something that never finishes.

Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2)
before we go to wait on the writeback.  The page fault path, which is
the only path that triggers memcg oom killer since 3.12, shouldn't
require GFP_NOFS and so we shouldn't reintroduce the premature OOM
killer issue which was originally addressed by the heuristic.

As per David Chinner the xfs is doing similar thing since 2.6.15 already
so ext4 is not the only affected filesystem.  Moreover he notes:

: For example: IO completion might require unwritten extent conversion
: which executes filesystem transactions and GFP_NOFS allocations. The
: writeback flag on the pages can not be cleared until unwritten
: extent conversion completes. Hence memory reclaim cannot wait on
: page writeback to complete in GFP_NOFS context because it is not
: safe to do so, memcg reclaim or otherwise.

Cc: [email protected] # 3.9+
[[email protected]: corrected the control flow]
Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages")
Reported-by: Nikolay Borisov <[email protected]>
Signed-off-by: Michal Hocko <[email protected]>
Signed-off-by: Hugh Dickins <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
dabrace pushed a commit that referenced this pull request Apr 11, 2016
Several commits relating to setting power have been introducing
problems by putting driver-specific rules into generic SDHCI code.

Krzysztof Kozlowski reported that after commit 918f4cb ("mmc:
sdhci: restore behavior when setting VDD via external regulator")
on Trats2 board there are warnings for invalid VDD  value (2.8V):

[    3.119656] ------------[ cut here ]------------
[    3.119666] WARNING: CPU: 3 PID: 90 at
../drivers/mmc/host/sdhci.c:1234 sdhci_do_set_ios+0x4cc/0x5e0
[    3.119669] mmc0: Invalid vdd 0x10
[    3.119673] Modules linked in:
[    3.119679] CPU: 3 PID: 90 Comm: kworker/3:1 Tainted: G        W
   4.5.0-next-20160324 #23
[    3.119681] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[    3.119690] Workqueue: events_freezable mmc_rescan
[    3.119708] [<c010e0ac>] (unwind_backtrace) from [<c010ae10>]
(show_stack+0x10/0x14)
[    3.119719] [<c010ae10>] (show_stack) from [<c0323260>]
(dump_stack+0x88/0x9c)
[    3.119728] [<c0323260>] (dump_stack) from [<c011b754>] (__warn+0xe8/0x100)
[    3.119734] [<c011b754>] (__warn) from [<c011b7a4>]
(warn_slowpath_fmt+0x38/0x48)
[    3.119740] [<c011b7a4>] (warn_slowpath_fmt) from [<c0527d28>]
(sdhci_do_set_ios+0x4cc/0x5e0)
[    3.119748] [<c0527d28>] (sdhci_do_set_ios) from [<c0528018>]
(sdhci_runtime_resume_host+0x60/0x114)
[    3.119758] [<c0528018>] (sdhci_runtime_resume_host) from
[<c0402570>] (__rpm_callback+0x2c/0x60)
[    3.119767] [<c0402570>] (__rpm_callback) from [<c04025c4>]
(rpm_callback+0x20/0x80)
[    3.119773] [<c04025c4>] (rpm_callback) from [<c04034b8>]
(rpm_resume+0x36c/0x558)
[    3.119780] [<c04034b8>] (rpm_resume) from [<c04036f0>]
(__pm_runtime_resume+0x4c/0x64)
[    3.119788] [<c04036f0>] (__pm_runtime_resume) from [<c0512728>]
(__mmc_claim_host+0x170/0x1b0)
[    3.119795] [<c0512728>] (__mmc_claim_host) from [<c0514e2c>]
(mmc_rescan+0x54/0x348)
[    3.119807] [<c0514e2c>] (mmc_rescan) from [<c0130dac>]
(process_one_work+0x120/0x3f4)
[    3.119815] [<c0130dac>] (process_one_work) from [<c01310b8>]
(worker_thread+0x38/0x554)
[    3.119823] [<c01310b8>] (worker_thread) from [<c01365a4>]
(kthread+0xdc/0xf4)
[    3.119831] [<c01365a4>] (kthread) from [<c0107878>]
(ret_from_fork+0x14/0x3c)
[    3.119834] ---[ end trace a22d652aa3276886 ]---

Fix by adding a 'set_power' callback and restoring the default
behaviour prior to commit 918f4cb ("mmc: sdhci: restore
behavior when setting VDD via external regulator").  The desired
behaviour of that commit is gotten by having sdhci-pxav3 provide
its own set_power callback.

Reported-by: Krzysztof Kozlowski <[email protected]>
Link: http://lkml.kernel.org/r/CAJKOXPcGDnPm-Ykh6wHqV1YxfTaov5E8iVqBoBn4OJc7BnhgEQ@mail.gmail.com
Fixes: 918f4cb ("mmc: sdhci: restore behavior when setting VDD...)
Tested-by: Krzysztof Kozlowski <[email protected]>
Tested-by: Ludovic Desroches <[email protected]>
Signed-off-by: Adrian Hunter <[email protected]>
Cc: [email protected] # v4.5+
Reviewed-by: Jisheng Zhang <[email protected]>
Tested-by: Jisheng Zhang <[email protected]>
Tested-by: Jaehoon Chung <[email protected]>
Tested-by: Anand Moon <[email protected]>
Signed-off-by: Ulf Hansson <[email protected]>
dabrace pushed a commit that referenced this pull request May 24, 2016
This fixes the following checkpatch.pl warning:

  WARNING: __packed is preferred over __attribute__((packed))
  #23: FILE: export.h:23:
  +} __attribute__ ((packed));

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ryusuke Konishi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
dabrace pushed a commit that referenced this pull request May 31, 2016
When btrfs_copy_from_user isn't able to copy all of the pages, we need
to adjust our accounting to reflect the work that was actually done.

Commit 2e78c92 changed around the decisions a little and we ended up
skipping the accounting adjustments some of the time.  This commit makes
sure that when we don't copy anything at all, we still hop into
the adjustments, and switches to release_bytes instead of write_bytes,
since write_bytes isn't aligned.

The accounting errors led to warnings during btrfs_destroy_inode:

[   70.847532] WARNING: CPU: 10 PID: 514 at fs/btrfs/inode.c:9350 btrfs_destroy_inode+0x2b3/0x2c0
[   70.847536] Modules linked in: i2c_piix4 virtio_net i2c_core input_leds button led_class serio_raw acpi_cpufreq sch_fq_codel autofs4 virtio_blk
[   70.847538] CPU: 10 PID: 514 Comm: umount Tainted: G        W 4.6.0-rc6_00062_g2997da1-dirty #23
[   70.847539] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.0-1.fc24 04/01/2014
[   70.847542]  0000000000000000 ffff880ff5cafab8 ffffffff8149d5e9 0000000000000202
[   70.847543]  0000000000000000 0000000000000000 0000000000000000 ffff880ff5cafb08
[   70.847547]  ffffffff8107bdfd ffff880ff5cafaf8 000024868120013d ffff880ff5cafb28
[   70.847547] Call Trace:
[   70.847550]  [<ffffffff8149d5e9>] dump_stack+0x51/0x78
[   70.847551]  [<ffffffff8107bdfd>] __warn+0xfd/0x120
[   70.847553]  [<ffffffff8107be3d>] warn_slowpath_null+0x1d/0x20
[   70.847555]  [<ffffffff8139c9e3>] btrfs_destroy_inode+0x2b3/0x2c0
[   70.847556]  [<ffffffff812003a1>] ? __destroy_inode+0x71/0x140
[   70.847558]  [<ffffffff812004b3>] destroy_inode+0x43/0x70
[   70.847559]  [<ffffffff810b7b5f>] ? wake_up_bit+0x2f/0x40
[   70.847560]  [<ffffffff81200c68>] evict+0x148/0x1d0
[   70.847562]  [<ffffffff81398ade>] ? start_transaction+0x3de/0x460
[   70.847564]  [<ffffffff81200d49>] dispose_list+0x59/0x80
[   70.847565]  [<ffffffff81201ba0>] evict_inodes+0x180/0x190
[   70.847566]  [<ffffffff812191ff>] ? __sync_filesystem+0x3f/0x50
[   70.847568]  [<ffffffff811e95f8>] generic_shutdown_super+0x48/0x100
[   70.847569]  [<ffffffff810b75c0>] ? woken_wake_function+0x20/0x20
[   70.847571]  [<ffffffff811e9796>] kill_anon_super+0x16/0x30
[   70.847573]  [<ffffffff81365cde>] btrfs_kill_super+0x1e/0x130
[   70.847574]  [<ffffffff811e99be>] deactivate_locked_super+0x4e/0x90
[   70.847576]  [<ffffffff811e9e61>] deactivate_super+0x51/0x70
[   70.847577]  [<ffffffff8120536f>] cleanup_mnt+0x3f/0x80
[   70.847579]  [<ffffffff81205402>] __cleanup_mnt+0x12/0x20
[   70.847581]  [<ffffffff81098358>] task_work_run+0x68/0xa0
[   70.847582]  [<ffffffff810022b6>] exit_to_usermode_loop+0xd6/0xe0
[   70.847583]  [<ffffffff81002e1d>] do_syscall_64+0xbd/0x170
[   70.847586]  [<ffffffff817d4dbc>] entry_SYSCALL64_slow_path+0x25/0x25

This is the test program I used to force short returns from
btrfs_copy_from_user

void *dontneed(void *arg)
{
	char *p = arg;
	int ret;

	while(1) {
		ret = madvise(p, BUFSIZE/4, MADV_DONTNEED);
		if (ret) {
			perror("madvise");
			exit(1);
		}
	}
}

int main(int ac, char **av) {
	int ret;
	int fd;
	char *filename;
	unsigned long offset;
	char *buf;
	int i;
	pthread_t tid;

	if (ac != 2) {
		fprintf(stderr, "usage: dammitdave filename\n");
		exit(1);
	}

	buf = mmap(NULL, BUFSIZE, PROT_READ|PROT_WRITE,
		   MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
	if (buf == MAP_FAILED) {
		perror("mmap");
		exit(1);
	}
	memset(buf, 'a', BUFSIZE);
	filename = av[1];

	ret = pthread_create(&tid, NULL, dontneed, buf);
	if (ret) {
		fprintf(stderr, "error %d from pthread_create\n", ret);
		exit(1);
	}

	ret = pthread_detach(tid);
	if (ret) {
		fprintf(stderr, "pthread detach failed %d\n", ret);
		exit(1);
	}

	while (1) {
		fd = open(filename, O_RDWR | O_CREAT, 0600);
		if (fd < 0) {
			perror("open");
			exit(1);
		}

		for (i = 0; i < ROUNDS; i++) {
			int this_write = BUFSIZE;

			offset = rand() % MAXSIZE;
			ret = pwrite(fd, buf, this_write, offset);
			if (ret < 0) {
				perror("pwrite");
				exit(1);
			} else if (ret != this_write) {
				fprintf(stderr, "short write to %s offset %lu ret %d\n",
					filename, offset, ret);
				exit(1);
			}
			if (i == ROUNDS - 1) {
				ret = sync_file_range(fd, offset, 4096,
				    SYNC_FILE_RANGE_WRITE);
				if (ret < 0) {
					perror("sync_file_range");
					exit(1);
				}
			}
		}
		ret = ftruncate(fd, 0);
		if (ret < 0) {
			perror("ftruncate");
			exit(1);
		}
		ret = close(fd);
		if (ret) {
			perror("close");
			exit(1);
		}
		ret = unlink(filename);
		if (ret) {
			perror("unlink");
			exit(1);
		}

	}
	return 0;
}

Signed-off-by: Chris Mason <[email protected]>
Reported-by: Dave Jones <[email protected]>
Fixes: 2e78c92
cc: [email protected] # v4.6
Signed-off-by: Chris Mason <[email protected]>
dabrace pushed a commit that referenced this pull request Mar 15, 2017
As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 #8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 #9 [] tcp_rcv_established at ffffffff81580b64
#10 [] tcp_v4_do_rcv at ffffffff8158b54a
#11 [] tcp_v4_rcv at ffffffff8158cd02
#12 [] ip_local_deliver_finish at ffffffff815668f4
#13 [] ip_local_deliver at ffffffff81566bd9
#14 [] ip_rcv_finish at ffffffff8156656d
#15 [] ip_rcv at ffffffff81566f06
#16 [] __netif_receive_skb_core at ffffffff8152b3a2
#17 [] __netif_receive_skb at ffffffff8152b608
#18 [] netif_receive_skb at ffffffff8152b690
#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
#21 [] net_rx_action at ffffffff8152bac2
#22 [] __do_softirq at ffffffff81084b4f
#23 [] call_softirq at ffffffff8164845c
#24 [] do_softirq at ffffffff81016fc5
#25 [] irq_exit at ffffffff81084ee5
#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)↩
 225 {↩
 226 ▹       const struct inet_connection_sock *icsk = inet_csk(sk);↩
 227 ▹       const struct dst_entry *dst = __sk_dst_get(sk);↩
 228 ↩
 229 ▹       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
 230 ▹       ▹       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
 231 }↩

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb3320 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <[email protected]>
Cc: Hannes Sowa <[email protected]>
Signed-off-by: Jon Maxwell <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
dabrace pushed a commit that referenced this pull request Jun 12, 2017
 WARNING: CPU: 3 PID: 2840 at arch/x86/kvm/vmx.c:10966 nested_vmx_vmexit+0xdcd/0xde0 [kvm_intel]
 CPU: 3 PID: 2840 Comm: qemu-system-x86 Tainted: G           OE   4.12.0-rc3+ #23
 RIP: 0010:nested_vmx_vmexit+0xdcd/0xde0 [kvm_intel]
 Call Trace:
  ? kvm_check_async_pf_completion+0xef/0x120 [kvm]
  ? rcu_read_lock_sched_held+0x79/0x80
  vmx_queue_exception+0x104/0x160 [kvm_intel]
  ? vmx_queue_exception+0x104/0x160 [kvm_intel]
  kvm_arch_vcpu_ioctl_run+0x1171/0x1ce0 [kvm]
  ? kvm_arch_vcpu_load+0x47/0x240 [kvm]
  ? kvm_arch_vcpu_load+0x62/0x240 [kvm]
  kvm_vcpu_ioctl+0x384/0x7b0 [kvm]
  ? kvm_vcpu_ioctl+0x384/0x7b0 [kvm]
  ? __fget+0xf3/0x210
  do_vfs_ioctl+0xa4/0x700
  ? __fget+0x114/0x210
  SyS_ioctl+0x79/0x90
  do_syscall_64+0x81/0x220
  entry_SYSCALL64_slow_path+0x25/0x25

This is triggered occasionally by running both win7 and win2016 in L2, in
addition, EPT is disabled on both L1 and L2. It can't be reproduced easily.

Commit 0b6ac34 (KVM: nVMX: Correct handling of exception injection) mentioned
that "KVM wants to inject page-faults which it got to the guest. This function
assumes it is called with the exit reason in vmcs02 being a #PF exception".
Commit e011c66 (KVM: nVMX: Check all exceptions for intercept during delivery to
L2) allows to check all exceptions for intercept during delivery to L2. However,
there is no guarantee the exit reason is exception currently, when there is an
external interrupt occurred on host, maybe a time interrupt for host which should
not be injected to guest, and somewhere queues an exception, then the function
nested_vmx_check_exception() will be called and the vmexit emulation codes will
try to emulate the "Acknowledge interrupt on exit" behavior, the warning is
triggered.

Reusing the exit reason from the L2->L0 vmexit is wrong in this case,
the reason must always be EXCEPTION_NMI when injecting an exception into
L1 as a nested vmexit.

Cc: Paolo Bonzini <[email protected]>
Cc: Radim Krčmář <[email protected]>
Signed-off-by: Wanpeng Li <[email protected]>
Fixes: e011c66 ("KVM: nVMX: Check all exceptions for intercept during delivery to L2")
Signed-off-by: Radim Krčmář <[email protected]>
dabrace pushed a commit that referenced this pull request Aug 23, 2017
syzkaller reported a double free [1], caused by the fact
that tun driver was not updated properly when priv_destructor
was added.

When/if register_netdevice() fails, priv_destructor() must have been
called already.

[1]
BUG: KASAN: double-free or invalid-free in selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023

CPU: 0 PID: 2919 Comm: syzkaller227220 Not tainted 4.13.0-rc4+ #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x7f/0x260 mm/kasan/report.c:252
 kasan_report_double_free+0x55/0x80 mm/kasan/report.c:333
 kasan_slab_free+0xa0/0xc0 mm/kasan/kasan.c:514
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xd3/0x260 mm/slab.c:3820
 selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023
 security_tun_dev_free_security+0x48/0x80 security/security.c:1512
 tun_set_iff drivers/net/tun.c:1884 [inline]
 __tun_chr_ioctl+0x2ce6/0x3d50 drivers/net/tun.c:2064
 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x443ff9
RSP: 002b:00007ffc34271f68 EFLAGS: 00000217 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443ff9
RDX: 0000000020533000 RSI: 00000000400454ca RDI: 0000000000000003
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401ce0
R13: 0000000000401d70 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 2919:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x101/0x6f0 mm/slab.c:3627
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:666 [inline]
 selinux_tun_dev_alloc_security+0x49/0x170 security/selinux/hooks.c:5012
 security_tun_dev_alloc_security+0x6d/0xa0 security/security.c:1506
 tun_set_iff drivers/net/tun.c:1839 [inline]
 __tun_chr_ioctl+0x1730/0x3d50 drivers/net/tun.c:2064
 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 2919:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x6e/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xd3/0x260 mm/slab.c:3820
 selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023
 security_tun_dev_free_security+0x48/0x80 security/security.c:1512
 tun_free_netdev+0x13b/0x1b0 drivers/net/tun.c:1563
 register_netdevice+0x8d0/0xee0 net/core/dev.c:7605
 tun_set_iff drivers/net/tun.c:1859 [inline]
 __tun_chr_ioctl+0x1caf/0x3d50 drivers/net/tun.c:2064
 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe

The buggy address belongs to the object at ffff8801d2843b40
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801d2843b40, ffff8801d2843b60)
The buggy address belongs to the page:
page:ffffea000660cea8 count:1 mapcount:0 mapping:ffff8801d2843000 index:0xffff8801d2843fc1
flags: 0x200000000000100(slab)
raw: 0200000000000100 ffff8801d2843000 ffff8801d2843fc1 000000010000003f
raw: ffffea0006626a40 ffffea00066141a0 ffff8801dbc00100
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d2843a00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d2843a80: 00 00 00 fc fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801d2843b00: 00 00 00 00 fc fc fc fc fb fb fb fb fc fc fc fc
                                           ^
 ffff8801d2843b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d2843c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc

==================================================================

Fixes: cf124db ("net: Fix inconsistent teardown and release of private netdev state.")
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
dabrace pushed a commit that referenced this pull request Sep 25, 2017
syzkaller reported following splat [1]

Since hard irq are disabled by the caller, bpf_map_free_id()
should not try to enable/disable BH.

Another solution would be to change htab_map_delete_elem() to
defer the free_htab_elem() call after
raw_spin_unlock_irqrestore(&b->lock, flags), but this might be not
enough to cover other code paths.

[1]
WARNING: CPU: 1 PID: 8052 at kernel/softirq.c:161 __local_bh_enable_ip
+0x1e/0x160 kernel/softirq.c:161
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 8052 Comm: syz-executor1 Not tainted 4.13.0-next-20170915+
#23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 panic+0x1e4/0x417 kernel/panic.c:181
 __warn+0x1c4/0x1d9 kernel/panic.c:542
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178
 do_trap_no_signal arch/x86/kernel/traps.c:212 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:261
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:__local_bh_enable_ip+0x1e/0x160 kernel/softirq.c:161
RSP: 0018:ffff8801cdcd7748 EFLAGS: 00010046
RAX: 0000000000000082 RBX: 0000000000000201 RCX: 0000000000000000
RDX: 1ffffffff0b5933c RSI: 0000000000000201 RDI: ffffffff85ac99e0
RBP: ffff8801cdcd7758 R08: ffffffff85b87158 R09: 1ffff10039b9aec6
R10: ffff8801c99f24c0 R11: 0000000000000002 R12: ffffffff817b0b47
R13: dffffc0000000000 R14: ffff8801cdcd77e8 R15: 0000000000000001
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
 _raw_spin_unlock_bh+0x30/0x40 kernel/locking/spinlock.c:207
 spin_unlock_bh include/linux/spinlock.h:361 [inline]
 bpf_map_free_id kernel/bpf/syscall.c:197 [inline]
 __bpf_map_put+0x267/0x320 kernel/bpf/syscall.c:227
 bpf_map_put+0x1a/0x20 kernel/bpf/syscall.c:235
 bpf_map_fd_put_ptr+0x15/0x20 kernel/bpf/map_in_map.c:96
 free_htab_elem+0xc3/0x1b0 kernel/bpf/hashtab.c:658
 htab_map_delete_elem+0x74d/0x970 kernel/bpf/hashtab.c:1063
 map_delete_elem kernel/bpf/syscall.c:633 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1479 [inline]
 SyS_bpf+0x2188/0x46a0 kernel/bpf/syscall.c:1451
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Fixes: f3f1c05 ("bpf: Introduce bpf_map ID")
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Acked-by: Martin KaFai Lau <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
dabrace pushed a commit that referenced this pull request Nov 1, 2017
Syzkaller found several variants of the lockup below by setting negative
values with the TUNSETSNDBUF ioctl.  This patch adds a sanity check
to both the tun and tap versions of this ioctl.

  watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [repro:2389]
  Modules linked in:
  irq event stamp: 329692056
  hardirqs last  enabled at (329692055): [<ffffffff824b8381>] _raw_spin_unlock_irqrestore+0x31/0x75
  hardirqs last disabled at (329692056): [<ffffffff824b9e58>] apic_timer_interrupt+0x98/0xb0
  softirqs last  enabled at (35659740): [<ffffffff824bc958>] __do_softirq+0x328/0x48c
  softirqs last disabled at (35659731): [<ffffffff811c796c>] irq_exit+0xbc/0xd0
  CPU: 0 PID: 2389 Comm: repro Not tainted 4.14.0-rc7 #23
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  task: ffff880009452140 task.stack: ffff880006a20000
  RIP: 0010:_raw_spin_lock_irqsave+0x11/0x80
  RSP: 0018:ffff880006a27c50 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
  RAX: ffff880009ac68d0 RBX: ffff880006a27ce0 RCX: 0000000000000000
  RDX: 0000000000000001 RSI: ffff880006a27ce0 RDI: ffff880009ac6900
  RBP: ffff880006a27c60 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000001 R11: 000000000063ff00 R12: ffff880009ac6900
  R13: ffff880006a27cf8 R14: 0000000000000001 R15: ffff880006a27cf8
  FS:  00007f4be4838700(0000) GS:ffff88000cc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000020101000 CR3: 0000000009616000 CR4: 00000000000006f0
  Call Trace:
   prepare_to_wait+0x26/0xc0
   sock_alloc_send_pskb+0x14e/0x270
   ? remove_wait_queue+0x60/0x60
   tun_get_user+0x2cc/0x19d0
   ? __tun_get+0x60/0x1b0
   tun_chr_write_iter+0x57/0x86
   __vfs_write+0x156/0x1e0
   vfs_write+0xf7/0x230
   SyS_write+0x57/0xd0
   entry_SYSCALL_64_fastpath+0x1f/0xbe
  RIP: 0033:0x7f4be4356df9
  RSP: 002b:00007ffc18101c08 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4be4356df9
  RDX: 0000000000000046 RSI: 0000000020101000 RDI: 0000000000000005
  RBP: 00007ffc18101c40 R08: 0000000000000001 R09: 0000000000000001
  R10: 0000000000000001 R11: 0000000000000293 R12: 0000559c75f64780
  R13: 00007ffc18101d30 R14: 0000000000000000 R15: 0000000000000000

Fixes: 33dccbb ("tun: Limit amount of queued packets per device")
Fixes: 20d29d7 ("net: macvtap driver")
Signed-off-by: Craig Gallek <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
dabrace pushed a commit that referenced this pull request Feb 27, 2018
Xtensa memory initialization code frees high memory pages without
checking whether they are in the reserved memory regions or not. That
results in invalid value of totalram_pages and duplicate page usage by
CMA and highmem. It produces a bunch of BUGs at startup looking like
this:

BUG: Bad page state in process swapper  pfn:70800
page:be60c000 count:0 mapcount:-127 mapping:  (null) index:0x1
flags: 0x80000000()
raw: 80000000 00000000 00000001 ffffff80 00000000 be60c014 be60c014 0000000a
page dumped because: nonzero mapcount
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Tainted: G    B            4.16.0-rc1-00015-g7928b2cbe55b-dirty #23
Stack:
 bd839d33 00000000 00000018 ba97b64c a106578c bd839d70 be60c000 00000000
 a1378054 bd86a000 00000003 ba97b64c a1066166 bd839da0 be60c000 ffe00000
 a1066b58 bd839dc0 be504000 00000000 000002f4 bd838000 00000000 0000001e
Call Trace:
 [<a1065734>] bad_page+0xac/0xd0
 [<a106578c>] free_pages_check_bad+0x34/0x4c
 [<a1066166>] __free_pages_ok+0xae/0x14c
 [<a1066b58>] __free_pages+0x30/0x64
 [<a1365de5>] init_cma_reserved_pageblock+0x35/0x44
 [<a13682dc>] cma_init_reserved_areas+0xf4/0x148
 [<a10034b8>] do_one_initcall+0x80/0xf8
 [<a1361c16>] kernel_init_freeable+0xda/0x13c
 [<a125b59d>] kernel_init+0x9/0xd0
 [<a1004304>] ret_from_kernel_thread+0xc/0x18

Only free high memory pages that are not reserved.

Cc: [email protected]
Signed-off-by: Max Filippov <[email protected]>
dabrace pushed a commit that referenced this pull request Mar 6, 2018
If m88d3103 chip ID is not recognized, the device is not initialized.

However, it returns from probe without any error, causing this OOPS:

[    7.689289] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[    7.689297] pgd = 7b0bd7a7
[    7.689302] [00000000] *pgd=00000000
[    7.689318] Internal error: Oops: 80000005 [#1] SMP ARM
[    7.689322] Modules linked in: dvb_usb_dvbsky(+) m88ds3103 dvb_usb_v2 dvb_core videobuf2_vmalloc videobuf2_memops videobuf2_core crc32_arm_ce videodev media
[    7.689358] CPU: 3 PID: 197 Comm: systemd-udevd Not tainted 4.15.0-mcc+ #23
[    7.689361] Hardware name: BCM2835
[    7.689367] PC is at 0x0
[    7.689382] LR is at m88ds3103_attach+0x194/0x1d0 [m88ds3103]
[    7.689386] pc : [<00000000>]    lr : [<bf0ae1ec>]    psr: 60000013
[    7.689391] sp : ed8e5c20  ip : ed8c1e00  fp : ed8945c0
[    7.689395] r10: ed894000  r9 : ed894378  r8 : eda736c0
[    7.689400] r7 : ed894070  r6 : ed8e5c44  r5 : bf0bb040  r4 : eda77600
[    7.689405] r3 : 00000000  r2 : 00000000  r1 : 00000000  r0 : eda77600
[    7.689412] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[    7.689417] Control: 10c5383d  Table: 2d8e806a  DAC: 00000051
[    7.689423] Process systemd-udevd (pid: 197, stack limit = 0xe9dbfb63)
[    7.689428] Stack: (0xed8e5c20 to 0xed8e6000)
[    7.689439] 5c20: ed853a80 eda73640 ed894000 ed8942c0 ed853a80 bf0b9e98 ed894070 bf0b9f10
[    7.689449] 5c40: 00000000 00000000 bf08c17c c08dfc50 00000000 00000000 00000000 00000000
[    7.689459] 5c60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    7.689468] 5c80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    7.689479] 5ca0: 00000000 00000000 ed8945c0 ed8942c0 ed894000 ed894830 bf0b9e98 00000000
[    7.689490] 5cc0: ed894378 bf0a3cb4 bf0bc3b0 0000533b ed920540 00000000 00000034 bf0a6434
[    7.689500] 5ce0: ee952070 ed826600 bf0a7038 bf0a2dd8 00000001 bf0a6768 bf0a2f90 ed8943c0
[    7.689511] 5d00: 00000000 c08eca68 ed826620 ed826620 00000000 ee952070 bf0bc034 ee952000
[    7.689521] 5d20: ed826600 bf0bb080 ffffffed c0aa9e9c c0aa9dac ed826620 c16edf6c c168c2c8
[    7.689531] 5d40: c16edf70 00000000 bf0bc034 0000000d 00000000 c08e268c bf0bb080 ed826600
[    7.689541] 5d60: bf0bc034 ed826654 ed826620 bf0bc034 c164c8bc 00000000 00000001 00000000
[    7.689553] 5d80: 00000028 c08e2948 00000000 bf0bc034 c08e2848 c08e0778 ee9f0a58 ed88bab4
[    7.689563] 5da0: bf0bc034 ed90ba80 c168c1f0 c08e1934 bf0bb3bc c17045ac bf0bc034 c164c8bc
[    7.689574] 5dc0: bf0bc034 bf0bb3bc ed91f564 c08e34ec bf0bc000 c164c8bc bf0bc034 c0aa8dc4
[    7.689584] 5de0: ffffe000 00000000 bf0bf000 ed91f600 ed91f564 c03021e4 00000001 00000000
[    7.689595] 5e00: c166e040 8040003f ed853a80 bf0bc448 00000000 c1678174 ed853a80 f0f22000
[    7.689605] 5e20: f0f21fff 8040003f 014000c0 ed91e700 ed91e700 c16d8e68 00000001 ed91e6c0
[    7.689615] 5e40: bf0bc400 00000001 bf0bc400 ed91f564 00000001 00000000 00000028 c03c9a24
[    7.689625] 5e60: 00000001 c03c8c94 ed8e5f50 ed8e5f50 00000001 bf0bc400 ed91f540 c03c8cb0
[    7.689637] 5e80: bf0bc40c 00007fff bf0bc400 c03c60b0 00000000 bf0bc448 00000028 c0e09684
[    7.689647] 5ea0: 00000002 bf0bc530 c1234bf8 bf0bc5dc bf0bc514 c10ebbe8 ffffe000 bf000000
[    7.689657] 5ec0: 00011538 00000000 ed8e5f48 00000000 00000000 00000000 00000000 00000000
[    7.689666] 5ee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    7.689676] 5f00: 00000000 00000000 7fffffff 00000000 00000013 b6e55a18 0000017b c0309104
[    7.689686] 5f20: ed8e4000 00000000 00510af0 c03c9430 7fffffff 00000000 00000003 00000000
[    7.689697] 5f40: 00000000 f0f0f000 00011538 00000000 f0f107b0 f0f0f000 00011538 f0f1fdb8
[    7.689707] 5f60: f0f1fbe8 f0f1b974 00004000 000041e0 bf0bc3d0 00000001 00000000 000024c4
[    7.689717] 5f80: 0000002d 0000002e 00000019 00000000 00000010 00000000 16894000 00000000
[    7.689727] 5fa0: 00000000 c0308f20 16894000 00000000 00000013 b6e55a18 00000000 b6e5652c
[    7.689737] 5fc0: 16894000 00000000 00000000 0000017b 00020000 00508110 00000000 00510af0
[    7.689748] 5fe0: bef68948 bef68938 b6e4d3d0 b6d32590 60000010 00000013 00000000 00000000
[    7.689790] [<bf0ae1ec>] (m88ds3103_attach [m88ds3103]) from [<bf0b9f10>] (dvbsky_s960c_attach+0x78/0x280 [dvb_usb_dvbsky])
[    7.689821] [<bf0b9f10>] (dvbsky_s960c_attach [dvb_usb_dvbsky]) from [<bf0a3cb4>] (dvb_usbv2_probe+0xa3c/0x1024 [dvb_usb_v2])
[    7.689849] [<bf0a3cb4>] (dvb_usbv2_probe [dvb_usb_v2]) from [<c0aa9e9c>] (usb_probe_interface+0xf0/0x2a8)
[    7.689869] [<c0aa9e9c>] (usb_probe_interface) from [<c08e268c>] (driver_probe_device+0x2f8/0x4b4)
[    7.689881] [<c08e268c>] (driver_probe_device) from [<c08e2948>] (__driver_attach+0x100/0x11c)
[    7.689895] [<c08e2948>] (__driver_attach) from [<c08e0778>] (bus_for_each_dev+0x4c/0x9c)
[    7.689909] [<c08e0778>] (bus_for_each_dev) from [<c08e1934>] (bus_add_driver+0x1c0/0x264)
[    7.689919] [<c08e1934>] (bus_add_driver) from [<c08e34ec>] (driver_register+0x78/0xf4)
[    7.689931] [<c08e34ec>] (driver_register) from [<c0aa8dc4>] (usb_register_driver+0x70/0x134)
[    7.689946] [<c0aa8dc4>] (usb_register_driver) from [<c03021e4>] (do_one_initcall+0x44/0x168)
[    7.689963] [<c03021e4>] (do_one_initcall) from [<c03c9a24>] (do_init_module+0x64/0x1f4)
[    7.689979] [<c03c9a24>] (do_init_module) from [<c03c8cb0>] (load_module+0x20a0/0x25c8)
[    7.689993] [<c03c8cb0>] (load_module) from [<c03c9430>] (SyS_finit_module+0xb4/0xec)
[    7.690007] [<c03c9430>] (SyS_finit_module) from [<c0308f20>] (ret_fast_syscall+0x0/0x54)
[    7.690018] Code: bad PC value

This may happen on normal circumstances, if, for some reason, the demod
hangs and start returning an invalid chip ID:

[   10.394395] m88ds3103 3-0068: Unknown device. Chip_id=00

So, change the logic to cause probe to fail with -ENODEV, preventing
the OOPS.

Detected while testing DVB MMAP patches on Raspberry Pi 3 with
DVBSky S960CI.

Cc: [email protected]
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
dabrace pushed a commit that referenced this pull request Mar 23, 2018
The attempt to join multicast group without ensuring that CMA device
exists will lead to the following crash reported by syzkaller.

[   64.076794] BUG: KASAN: null-ptr-deref in rdma_join_multicast+0x26e/0x12c0
[   64.076797] Read of size 8 at addr 00000000000000b0 by task join/691
[   64.076797]
[   64.076800] CPU: 1 PID: 691 Comm: join Not tainted 4.16.0-rc1-00219-gb97853b65b93 #23
[   64.076802] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-proj4
[   64.076803] Call Trace:
[   64.076809]  dump_stack+0x5c/0x77
[   64.076817]  kasan_report+0x163/0x380
[   64.085859]  ? rdma_join_multicast+0x26e/0x12c0
[   64.086634]  rdma_join_multicast+0x26e/0x12c0
[   64.087370]  ? rdma_disconnect+0xf0/0xf0
[   64.088579]  ? __radix_tree_replace+0xc3/0x110
[   64.089132]  ? node_tag_clear+0x81/0xb0
[   64.089606]  ? idr_alloc_u32+0x12e/0x1a0
[   64.090517]  ? __fprop_inc_percpu_max+0x150/0x150
[   64.091768]  ? tracing_record_taskinfo+0x10/0xc0
[   64.092340]  ? idr_alloc+0x76/0xc0
[   64.092951]  ? idr_alloc_u32+0x1a0/0x1a0
[   64.093632]  ? ucma_process_join+0x23d/0x460
[   64.094510]  ucma_process_join+0x23d/0x460
[   64.095199]  ? ucma_migrate_id+0x440/0x440
[   64.095696]  ? futex_wake+0x10b/0x2a0
[   64.096159]  ucma_join_multicast+0x88/0xe0
[   64.096660]  ? ucma_process_join+0x460/0x460
[   64.097540]  ? _copy_from_user+0x5e/0x90
[   64.098017]  ucma_write+0x174/0x1f0
[   64.098640]  ? ucma_resolve_route+0xf0/0xf0
[   64.099343]  ? rb_erase_cached+0x6c7/0x7f0
[   64.099839]  __vfs_write+0xc4/0x350
[   64.100622]  ? perf_syscall_enter+0xe4/0x5f0
[   64.101335]  ? kernel_read+0xa0/0xa0
[   64.103525]  ? perf_sched_cb_inc+0xc0/0xc0
[   64.105510]  ? syscall_exit_register+0x2a0/0x2a0
[   64.107359]  ? __switch_to+0x351/0x640
[   64.109285]  ? fsnotify+0x899/0x8f0
[   64.111610]  ? fsnotify_unmount_inodes+0x170/0x170
[   64.113876]  ? __fsnotify_update_child_dentry_flags+0x30/0x30
[   64.115813]  ? ring_buffer_record_is_on+0xd/0x20
[   64.117824]  ? __fget+0xa8/0xf0
[   64.119869]  vfs_write+0xf7/0x280
[   64.122001]  SyS_write+0xa1/0x120
[   64.124213]  ? SyS_read+0x120/0x120
[   64.126644]  ? SyS_read+0x120/0x120
[   64.128563]  do_syscall_64+0xeb/0x250
[   64.130732]  entry_SYSCALL_64_after_hwframe+0x21/0x86
[   64.132984] RIP: 0033:0x7f5c994ade99
[   64.135699] RSP: 002b:00007f5c99b97d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   64.138740] RAX: ffffffffffffffda RBX: 00000000200001e4 RCX: 00007f5c994ade99
[   64.141056] RDX: 00000000000000a0 RSI: 00000000200001c0 RDI: 0000000000000015
[   64.143536] RBP: 00007f5c99b97ec0 R08: 0000000000000000 R09: 0000000000000000
[   64.146017] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5c99b97fc0
[   64.148608] R13: 0000000000000000 R14: 00007fff660e1c40 R15: 00007f5c99b989c0
[   64.151060]
[   64.153703] Disabling lock debugging due to kernel taint
[   64.156032] BUG: unable to handle kernel NULL pointer dereference at 00000000000000b0
[   64.159066] IP: rdma_join_multicast+0x26e/0x12c0
[   64.161451] PGD 80000001d0298067 P4D 80000001d0298067 PUD 1dea39067 PMD 0
[   64.164442] Oops: 0000 [#1] SMP KASAN PTI
[   64.166817] CPU: 1 PID: 691 Comm: join Tainted: G    B 4.16.0-rc1-00219-gb97853b65b93 #23
[   64.170004] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-proj4
[   64.174985] RIP: 0010:rdma_join_multicast+0x26e/0x12c0
[   64.177246] RSP: 0018:ffff8801c8207860 EFLAGS: 00010282
[   64.179901] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff94789522
[   64.183344] RDX: 1ffffffff2d50fa5 RSI: 0000000000000297 RDI: 0000000000000297
[   64.186237] RBP: ffff8801c8207a50 R08: 0000000000000000 R09: ffffed0039040ea7
[   64.189328] R10: 0000000000000001 R11: ffffed0039040ea6 R12: 0000000000000000
[   64.192634] R13: 0000000000000000 R14: ffff8801e2022800 R15: ffff8801d4ac2400
[   64.196105] FS:  00007f5c99b98700(0000) GS:ffff8801e5d00000(0000) knlGS:0000000000000000
[   64.199211] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   64.202046] CR2: 00000000000000b0 CR3: 00000001d1c48004 CR4: 00000000003606a0
[   64.205032] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   64.208221] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   64.211554] Call Trace:
[   64.213464]  ? rdma_disconnect+0xf0/0xf0
[   64.216124]  ? __radix_tree_replace+0xc3/0x110
[   64.219337]  ? node_tag_clear+0x81/0xb0
[   64.222140]  ? idr_alloc_u32+0x12e/0x1a0
[   64.224422]  ? __fprop_inc_percpu_max+0x150/0x150
[   64.226588]  ? tracing_record_taskinfo+0x10/0xc0
[   64.229763]  ? idr_alloc+0x76/0xc0
[   64.232186]  ? idr_alloc_u32+0x1a0/0x1a0
[   64.234505]  ? ucma_process_join+0x23d/0x460
[   64.237024]  ucma_process_join+0x23d/0x460
[   64.240076]  ? ucma_migrate_id+0x440/0x440
[   64.243284]  ? futex_wake+0x10b/0x2a0
[   64.245302]  ucma_join_multicast+0x88/0xe0
[   64.247783]  ? ucma_process_join+0x460/0x460
[   64.250841]  ? _copy_from_user+0x5e/0x90
[   64.253878]  ucma_write+0x174/0x1f0
[   64.257008]  ? ucma_resolve_route+0xf0/0xf0
[   64.259877]  ? rb_erase_cached+0x6c7/0x7f0
[   64.262746]  __vfs_write+0xc4/0x350
[   64.265537]  ? perf_syscall_enter+0xe4/0x5f0
[   64.267792]  ? kernel_read+0xa0/0xa0
[   64.270358]  ? perf_sched_cb_inc+0xc0/0xc0
[   64.272575]  ? syscall_exit_register+0x2a0/0x2a0
[   64.275367]  ? __switch_to+0x351/0x640
[   64.277700]  ? fsnotify+0x899/0x8f0
[   64.280530]  ? fsnotify_unmount_inodes+0x170/0x170
[   64.283156]  ? __fsnotify_update_child_dentry_flags+0x30/0x30
[   64.286182]  ? ring_buffer_record_is_on+0xd/0x20
[   64.288749]  ? __fget+0xa8/0xf0
[   64.291136]  vfs_write+0xf7/0x280
[   64.292972]  SyS_write+0xa1/0x120
[   64.294965]  ? SyS_read+0x120/0x120
[   64.297474]  ? SyS_read+0x120/0x120
[   64.299751]  do_syscall_64+0xeb/0x250
[   64.301826]  entry_SYSCALL_64_after_hwframe+0x21/0x86
[   64.304352] RIP: 0033:0x7f5c994ade99
[   64.306711] RSP: 002b:00007f5c99b97d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   64.309577] RAX: ffffffffffffffda RBX: 00000000200001e4 RCX: 00007f5c994ade99
[   64.312334] RDX: 00000000000000a0 RSI: 00000000200001c0 RDI: 0000000000000015
[   64.315783] RBP: 00007f5c99b97ec0 R08: 0000000000000000 R09: 0000000000000000
[   64.318365] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5c99b97fc0
[   64.320980] R13: 0000000000000000 R14: 00007fff660e1c40 R15: 00007f5c99b989c0
[   64.323515] Code: e8 e8 79 08 ff 4c 89 ff 45 0f b6 a7 b8 01 00 00 e8 68 7c 08 ff 49 8b 1f 4d 89 e5 49 c1 e4 04 48 8
[   64.330753] RIP: rdma_join_multicast+0x26e/0x12c0 RSP: ffff8801c8207860
[   64.332979] CR2: 00000000000000b0
[   64.335550] ---[ end trace 0c00c17a408849c1 ]---

Reported-by: <[email protected]>
Fixes: c8f6a36 ("RDMA/cma: Add multicast communication support")
Signed-off-by: Leon Romanovsky <[email protected]>
Reviewed-by: Sean Hefty <[email protected]>
Signed-off-by: Doug Ledford <[email protected]>
dabrace pushed a commit that referenced this pull request May 21, 2018
syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Jiri Benc <[email protected]>
Reported-by: syzbot <[email protected]>
Acked-by: Jiri Benc <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
dabrace pushed a commit that referenced this pull request Jul 24, 2018
Crash dump shows following instructions

crash> bt
PID: 0      TASK: ffffffffbe412480  CPU: 0   COMMAND: "swapper/0"
 #0 [ffff891ee0003868] machine_kexec at ffffffffbd063ef1
 #1 [ffff891ee00038c8] __crash_kexec at ffffffffbd12b6f2
 #2 [ffff891ee0003998] crash_kexec at ffffffffbd12c84c
 #3 [ffff891ee00039b8] oops_end at ffffffffbd030f0a
 #4 [ffff891ee00039e0] no_context at ffffffffbd074643
 #5 [ffff891ee0003a40] __bad_area_nosemaphore at ffffffffbd07496e
 #6 [ffff891ee0003a90] bad_area_nosemaphore at ffffffffbd074a64
 #7 [ffff891ee0003aa0] __do_page_fault at ffffffffbd074b0a
 #8 [ffff891ee0003b18] do_page_fault at ffffffffbd074fc8
 #9 [ffff891ee0003b50] page_fault at ffffffffbda01925
    [exception RIP: qlt_schedule_sess_for_deletion+15]
    RIP: ffffffffc02e526f  RSP: ffff891ee0003c08  RFLAGS: 00010046
    RAX: 0000000000000000  RBX: 0000000000000000  RCX: ffffffffc0307847
    RDX: 00000000000020e6  RSI: ffff891edbc377c8  RDI: 0000000000000000
    RBP: ffff891ee0003c18   R8: ffffffffc02f0b20   R9: 0000000000000250
    R10: 0000000000000258  R11: 000000000000b780  R12: ffff891ed9b43000
    R13: 00000000000000f0  R14: 0000000000000006  R15: ffff891edbc377c8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #10 [ffff891ee0003c20] qla2x00_fcport_event_handler at ffffffffc02853d3 [qla2xxx]
 #11 [ffff891ee0003cf0] __dta_qla24xx_async_gnl_sp_done_333 at ffffffffc0285a1d [qla2xxx]
 #12 [ffff891ee0003de8] qla24xx_process_response_queue at ffffffffc02a2eb5 [qla2xxx]
 #13 [ffff891ee0003e88] qla24xx_msix_rsp_q at ffffffffc02a5403 [qla2xxx]
 #14 [ffff891ee0003ec0] __handle_irq_event_percpu at ffffffffbd0f4c59
 #15 [ffff891ee0003f10] handle_irq_event_percpu at ffffffffbd0f4e02
 #16 [ffff891ee0003f40] handle_irq_event at ffffffffbd0f4e90
 #17 [ffff891ee0003f68] handle_edge_irq at ffffffffbd0f8984
 #18 [ffff891ee0003f88] handle_irq at ffffffffbd0305d5
 #19 [ffff891ee0003fb8] do_IRQ at ffffffffbda02a18
 --- <IRQ stack> ---
 #20 [ffffffffbe403d30] ret_from_intr at ffffffffbda0094e
    [exception RIP: unknown or invalid address]
    RIP: 000000000000001f  RSP: 0000000000000000  RFLAGS: fff3b8c2091ebb3f
    RAX: ffffbba5a0000200  RBX: 0000be8cdfa8f9fa  RCX: 0000000000000018
    RDX: 0000000000000101  RSI: 000000000000015d  RDI: 0000000000000193
    RBP: 0000000000000083   R8: ffffffffbe403e38   R9: 0000000000000002
    R10: 0000000000000000  R11: ffffffffbe56b820  R12: ffff891ee001cf00
    R13: ffffffffbd11c0a4  R14: ffffffffbe403d60  R15: 0000000000000001
    ORIG_RAX: ffff891ee0022ac0  CS: 0000  SS: ffffffffffffffb9
 bt: WARNING: possibly bogus exception frame
 #21 [ffffffffbe403dd8] cpuidle_enter_state at ffffffffbd67c6fd
 #22 [ffffffffbe403e40] cpuidle_enter at ffffffffbd67c907
 #23 [ffffffffbe403e50] call_cpuidle at ffffffffbd0d98f3
 #24 [ffffffffbe403e60] do_idle at ffffffffbd0d9b42
 #25 [ffffffffbe403e98] cpu_startup_entry at ffffffffbd0d9da3
 #26 [ffffffffbe403ec0] rest_init at ffffffffbd81d4aa
 #27 [ffffffffbe403ed0] start_kernel at ffffffffbe67d2ca
 #28 [ffffffffbe403f28] x86_64_start_reservations at ffffffffbe67c675
 #29 [ffffffffbe403f38] x86_64_start_kernel at ffffffffbe67c6eb
 #30 [ffffffffbe403f50] secondary_startup_64 at ffffffffbd0000d5

Fixes: 040036b ("scsi: qla2xxx: Delay loop id allocation at login")
Cc: <[email protected]> # v4.17+
Signed-off-by: Chuck Anderson <[email protected]>
Signed-off-by: Himanshu Madhani <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
dabrace pushed a commit that referenced this pull request Nov 12, 2018
Increase kasan instrumented kernel stack size from 32k to 64k. Other
architectures seems to get away with just doubling kernel stack size under
kasan, but on s390 this appears to be not enough due to bigger frame size.
The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE
vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting
stack overflow is fs sync on xfs filesystem:

 #0 [9a0681e8]  704 bytes  check_usage at 34b1fc
 #1 [9a0684a8]  432 bytes  check_usage at 34c710
 #2 [9a068658]  1048 bytes  validate_chain at 35044a
 #3 [9a068a70]  312 bytes  __lock_acquire at 3559fe
 #4 [9a068ba8]  440 bytes  lock_acquire at 3576ee
 #5 [9a068d60]  104 bytes  _raw_spin_lock at 21b44e0
 #6 [9a068dc8]  1992 bytes  enqueue_entity at 2dbf72
 #7 [9a069590]  1496 bytes  enqueue_task_fair at 2df5f0
 #8 [9a069b68]  64 bytes  ttwu_do_activate at 28f438
 #9 [9a069ba8]  552 bytes  try_to_wake_up at 298c4c
 #10 [9a069dd0]  168 bytes  wake_up_worker at 23f97c
 #11 [9a069e78]  200 bytes  insert_work at 23fc2e
 #12 [9a069f40]  648 bytes  __queue_work at 2487c0
 #13 [9a06a1c8]  200 bytes  __queue_delayed_work at 24db28
 #14 [9a06a290]  248 bytes  mod_delayed_work_on at 24de84
 #15 [9a06a388]  24 bytes  kblockd_mod_delayed_work_on at 153e2a0
 #16 [9a06a3a0]  288 bytes  __blk_mq_delay_run_hw_queue at 158168c
 #17 [9a06a4c0]  192 bytes  blk_mq_run_hw_queue at 1581a3c
 #18 [9a06a580]  184 bytes  blk_mq_sched_insert_requests at 15a2192
 #19 [9a06a638]  1024 bytes  blk_mq_flush_plug_list at 1590f3a
 #20 [9a06aa38]  704 bytes  blk_flush_plug_list at 1555028
 #21 [9a06acf8]  320 bytes  schedule at 219e476
 #22 [9a06ae38]  760 bytes  schedule_timeout at 21b0aac
 #23 [9a06b130]  408 bytes  wait_for_common at 21a1706
 #24 [9a06b2c8]  360 bytes  xfs_buf_iowait at fa1540
 #25 [9a06b430]  256 bytes  __xfs_buf_submit at fadae6
 #26 [9a06b530]  264 bytes  xfs_buf_read_map at fae3f6
 #27 [9a06b638]  656 bytes  xfs_trans_read_buf_map at 10ac9a8
 #28 [9a06b8c8]  304 bytes  xfs_btree_kill_root at e72426
 #29 [9a06b9f8]  288 bytes  xfs_btree_lookup_get_block at e7bc5e
 #30 [9a06bb18]  624 bytes  xfs_btree_lookup at e7e1a6
 #31 [9a06bd88]  2664 bytes  xfs_alloc_ag_vextent_near at dfa070
 #32 [9a06c7f0]  144 bytes  xfs_alloc_ag_vextent at dff3ca
 #33 [9a06c880]  1128 bytes  xfs_alloc_vextent at e05fce
 #34 [9a06cce8]  584 bytes  xfs_bmap_btalloc at e58342
 #35 [9a06cf30]  1336 bytes  xfs_bmapi_write at e618de
 #36 [9a06d468]  776 bytes  xfs_iomap_write_allocate at ff678e
 #37 [9a06d770]  720 bytes  xfs_map_blocks at f82af8
 #38 [9a06da40]  928 bytes  xfs_writepage_map at f83cd6
 #39 [9a06dde0]  320 bytes  xfs_do_writepage at f85872
 #40 [9a06df20]  1320 bytes  write_cache_pages at 73dfe8
 #41 [9a06e448]  208 bytes  xfs_vm_writepages at f7f892
 #42 [9a06e518]  88 bytes  do_writepages at 73fe6a
 #43 [9a06e570]  872 bytes  __writeback_single_inode at a20cb6
 #44 [9a06e8d8]  664 bytes  writeback_sb_inodes at a23be2
 #45 [9a06eb70]  296 bytes  __writeback_inodes_wb at a242e0
 #46 [9a06ec98]  928 bytes  wb_writeback at a2500e
 #47 [9a06f038]  848 bytes  wb_do_writeback at a260ae
 #48 [9a06f388]  536 bytes  wb_workfn at a28228
 #49 [9a06f5a0]  1088 bytes  process_one_work at 24a234
 #50 [9a06f9e0]  1120 bytes  worker_thread at 24ba26
 #51 [9a06fe40]  104 bytes  kthread at 26545a
 #52 [9a06fea8]             kernel_thread_starter at 21b6b62

To be able to increase the stack size to 64k reuse LLILL instruction
in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE
(65192) value as unsigned.

Reported-by: Benjamin Block <[email protected]>
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
dabrace pushed a commit that referenced this pull request Jan 21, 2019
and use smaller/on-stack buffer instead

The motivation for this change was lockdep splat like below.

| potentially unexpected fatal signal 11.
| BUG: sleeping function called from invalid context at ../mm/page_alloc.c:4317
| in_atomic(): 1, irqs_disabled(): 0, pid: 57, name: segv
| no locks held by segv/57.
| Preemption disabled at:
| [<8182f17e>] get_signal+0x4a6/0x7c4
| CPU: 0 PID: 57 Comm: segv Not tainted 4.17.0+ #23
|
| Stack Trace:
|  arc_unwind_core.constprop.1+0xd0/0xf4
|  __might_sleep+0x1f6/0x234
|  __get_free_pages+0x174/0xca0
|  show_regs+0x22/0x330
|  get_signal+0x4ac/0x7c4     # print_fatal_signals() -> preempt_disable()
|  do_signal+0x30/0x224
|  resume_user_mode_begin+0x90/0xd8

So signal handling core calls show_regs() with preemption disabled but
an ensuing GFP_KERNEL page allocator call is flagged by lockdep.

We could have switched to GFP_NOWAIT, but turns out that is not enough
anways and eliding page allocator call leads to less code and
instruction traces to sift thru when debugging pesky crashes.

FWIW, this patch doesn't cure the lockdep splat (which next patch does).

Reviewed-by: William Kucharski <[email protected]>
Signed-off-by: Vineet Gupta <[email protected]>
dabrace pushed a commit that referenced this pull request Mar 5, 2019
wake_up_locked() may but does not have to be called with interrupts
disabled. Since the fuse filesystem calls wake_up_locked() without
disabling interrupts aio_poll_wake() may be called with interrupts
enabled. Since the kioctx.ctx_lock may be acquired from IRQ context,
all code that acquires that lock from thread context must disable
interrupts. Hence change the spin_trylock() call in aio_poll_wake()
into a spin_trylock_irqsave() call. This patch fixes the following
lockdep complaint:

=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
5.0.0-rc4-next-20190131 #23 Not tainted
-----------------------------------------------------
syz-executor2/13779 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
0000000098ac1230 (&fiq->waitq){+.+.}, at: spin_lock include/linux/spinlock.h:329 [inline]
0000000098ac1230 (&fiq->waitq){+.+.}, at: aio_poll fs/aio.c:1772 [inline]
0000000098ac1230 (&fiq->waitq){+.+.}, at: __io_submit_one fs/aio.c:1875 [inline]
0000000098ac1230 (&fiq->waitq){+.+.}, at: io_submit_one+0xedf/0x1cf0 fs/aio.c:1908

and this task is already holding:
000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline]
000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1771 [inline]
000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one fs/aio.c:1875 [inline]
000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: io_submit_one+0xeb6/0x1cf0 fs/aio.c:1908
which would create a new lock dependency:
 (&(&ctx->ctx_lock)->rlock){..-.} -> (&fiq->waitq){+.+.}

but this new dependency connects a SOFTIRQ-irq-safe lock:
 (&(&ctx->ctx_lock)->rlock){..-.}

... which became SOFTIRQ-irq-safe at:
  lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
  __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
  _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160
  spin_lock_irq include/linux/spinlock.h:354 [inline]
  free_ioctx_users+0x2d/0x4a0 fs/aio.c:610
  percpu_ref_put_many include/linux/percpu-refcount.h:285 [inline]
  percpu_ref_put include/linux/percpu-refcount.h:301 [inline]
  percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline]
  percpu_ref_switch_to_atomic_rcu+0x3e7/0x520 lib/percpu-refcount.c:158
  __rcu_reclaim kernel/rcu/rcu.h:240 [inline]
  rcu_do_batch kernel/rcu/tree.c:2486 [inline]
  invoke_rcu_callbacks kernel/rcu/tree.c:2799 [inline]
  rcu_core+0x928/0x1390 kernel/rcu/tree.c:2780
  __do_softirq+0x266/0x95a kernel/softirq.c:292
  run_ksoftirqd kernel/softirq.c:654 [inline]
  run_ksoftirqd+0x8e/0x110 kernel/softirq.c:646
  smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164
  kthread+0x357/0x430 kernel/kthread.c:247
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

to a SOFTIRQ-irq-unsafe lock:
 (&fiq->waitq){+.+.}

... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
  __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
  _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
  spin_lock include/linux/spinlock.h:329 [inline]
  flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
  fuse_request_queue_background+0x2d1/0x580 fs/fuse/dev.c:676
  fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:687
  fuse_send_init fs/fuse/inode.c:989 [inline]
  fuse_fill_super+0x13bb/0x1730 fs/fuse/inode.c:1214
  mount_nodev+0x68/0x110 fs/super.c:1392
  fuse_mount+0x2d/0x40 fs/fuse/inode.c:1239
  legacy_get_tree+0xf2/0x200 fs/fs_context.c:590
  vfs_get_tree+0x123/0x450 fs/super.c:1481
  do_new_mount fs/namespace.c:2610 [inline]
  do_mount+0x1436/0x2c40 fs/namespace.c:2932
  ksys_mount+0xdb/0x150 fs/namespace.c:3148
  __do_sys_mount fs/namespace.c:3162 [inline]
  __se_sys_mount fs/namespace.c:3159 [inline]
  __x64_sys_mount+0xbe/0x150 fs/namespace.c:3159
  do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&fiq->waitq);
                               local_irq_disable();
                               lock(&(&ctx->ctx_lock)->rlock);
                               lock(&fiq->waitq);
  <Interrupt>
    lock(&(&ctx->ctx_lock)->rlock);

 *** DEADLOCK ***

1 lock held by syz-executor2/13779:
 #0: 000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline]
 #0: 000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1771 [inline]
 #0: 000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one fs/aio.c:1875 [inline]
 #0: 000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: io_submit_one+0xeb6/0x1cf0 fs/aio.c:1908

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (&(&ctx->ctx_lock)->rlock){..-.} {
   IN-SOFTIRQ-W at:
                    lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
                    __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
                    _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160
                    spin_lock_irq include/linux/spinlock.h:354 [inline]
                    free_ioctx_users+0x2d/0x4a0 fs/aio.c:610
                    percpu_ref_put_many include/linux/percpu-refcount.h:285 [inline]
                    percpu_ref_put include/linux/percpu-refcount.h:301 [inline]
                    percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline]
                    percpu_ref_switch_to_atomic_rcu+0x3e7/0x520 lib/percpu-refcount.c:158
                    __rcu_reclaim kernel/rcu/rcu.h:240 [inline]
                    rcu_do_batch kernel/rcu/tree.c:2486 [inline]
                    invoke_rcu_callbacks kernel/rcu/tree.c:2799 [inline]
                    rcu_core+0x928/0x1390 kernel/rcu/tree.c:2780
                    __do_softirq+0x266/0x95a kernel/softirq.c:292
                    run_ksoftirqd kernel/softirq.c:654 [inline]
                    run_ksoftirqd+0x8e/0x110 kernel/softirq.c:646
                    smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164
                    kthread+0x357/0x430 kernel/kthread.c:247
                    ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
   INITIAL USE at:
                   lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
                   __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
                   _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160
                   spin_lock_irq include/linux/spinlock.h:354 [inline]
                   __do_sys_io_cancel fs/aio.c:2052 [inline]
                   __se_sys_io_cancel fs/aio.c:2035 [inline]
                   __x64_sys_io_cancel+0xd5/0x5a0 fs/aio.c:2035
                   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
                   entry_SYSCALL_64_after_hwframe+0x49/0xbe
 }
 ... key      at: [<ffffffff8a574140>] __key.52370+0x0/0x40
 ... acquired at:
   lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
   __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
   _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
   spin_lock include/linux/spinlock.h:329 [inline]
   aio_poll fs/aio.c:1772 [inline]
   __io_submit_one fs/aio.c:1875 [inline]
   io_submit_one+0xedf/0x1cf0 fs/aio.c:1908
   __do_sys_io_submit fs/aio.c:1953 [inline]
   __se_sys_io_submit fs/aio.c:1923 [inline]
   __x64_sys_io_submit+0x1bd/0x580 fs/aio.c:1923
   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
-> (&fiq->waitq){+.+.} {
   HARDIRQ-ON-W at:
                    lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
                    __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                    _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
                    spin_lock include/linux/spinlock.h:329 [inline]
                    flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
                    fuse_request_queue_background+0x2d1/0x580 fs/fuse/dev.c:676
                    fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:687
                    fuse_send_init fs/fuse/inode.c:989 [inline]
                    fuse_fill_super+0x13bb/0x1730 fs/fuse/inode.c:1214
                    mount_nodev+0x68/0x110 fs/super.c:1392
                    fuse_mount+0x2d/0x40 fs/fuse/inode.c:1239
                    legacy_get_tree+0xf2/0x200 fs/fs_context.c:590
                    vfs_get_tree+0x123/0x450 fs/super.c:1481
                    do_new_mount fs/namespace.c:2610 [inline]
                    do_mount+0x1436/0x2c40 fs/namespace.c:2932
                    ksys_mount+0xdb/0x150 fs/namespace.c:3148
                    __do_sys_mount fs/namespace.c:3162 [inline]
                    __se_sys_mount fs/namespace.c:3159 [inline]
                    __x64_sys_mount+0xbe/0x150 fs/namespace.c:3159
                    do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
                    entry_SYSCALL_64_after_hwframe+0x49/0xbe
   SOFTIRQ-ON-W at:
                    lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
                    __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                    _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
                    spin_lock include/linux/spinlock.h:329 [inline]
                    flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
                    fuse_request_queue_background+0x2d1/0x580 fs/fuse/dev.c:676
                    fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:687
                    fuse_send_init fs/fuse/inode.c:989 [inline]
                    fuse_fill_super+0x13bb/0x1730 fs/fuse/inode.c:1214
                    mount_nodev+0x68/0x110 fs/super.c:1392
                    fuse_mount+0x2d/0x40 fs/fuse/inode.c:1239
                    legacy_get_tree+0xf2/0x200 fs/fs_context.c:590
                    vfs_get_tree+0x123/0x450 fs/super.c:1481
                    do_new_mount fs/namespace.c:2610 [inline]
                    do_mount+0x1436/0x2c40 fs/namespace.c:2932
                    ksys_mount+0xdb/0x150 fs/namespace.c:3148
                    __do_sys_mount fs/namespace.c:3162 [inline]
                    __se_sys_mount fs/namespace.c:3159 [inline]
                    __x64_sys_mount+0xbe/0x150 fs/namespace.c:3159
                    do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
                    entry_SYSCALL_64_after_hwframe+0x49/0xbe
   INITIAL USE at:
                   lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
                   __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                   _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
                   spin_lock include/linux/spinlock.h:329 [inline]
                   flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
                   fuse_request_queue_background+0x2d1/0x580 fs/fuse/dev.c:676
                   fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:687
                   fuse_send_init fs/fuse/inode.c:989 [inline]
                   fuse_fill_super+0x13bb/0x1730 fs/fuse/inode.c:1214
                   mount_nodev+0x68/0x110 fs/super.c:1392
                   fuse_mount+0x2d/0x40 fs/fuse/inode.c:1239
                   legacy_get_tree+0xf2/0x200 fs/fs_context.c:590
                   vfs_get_tree+0x123/0x450 fs/super.c:1481
                   do_new_mount fs/namespace.c:2610 [inline]
                   do_mount+0x1436/0x2c40 fs/namespace.c:2932
                   ksys_mount+0xdb/0x150 fs/namespace.c:3148
                   __do_sys_mount fs/namespace.c:3162 [inline]
                   __se_sys_mount fs/namespace.c:3159 [inline]
                   __x64_sys_mount+0xbe/0x150 fs/namespace.c:3159
                   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
                   entry_SYSCALL_64_after_hwframe+0x49/0xbe
 }
 ... key      at: [<ffffffff8a60dec0>] __key.43450+0x0/0x40
 ... acquired at:
   lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
   __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
   _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
   spin_lock include/linux/spinlock.h:329 [inline]
   aio_poll fs/aio.c:1772 [inline]
   __io_submit_one fs/aio.c:1875 [inline]
   io_submit_one+0xedf/0x1cf0 fs/aio.c:1908
   __do_sys_io_submit fs/aio.c:1953 [inline]
   __se_sys_io_submit fs/aio.c:1923 [inline]
   __x64_sys_io_submit+0x1bd/0x580 fs/aio.c:1923
   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

stack backtrace:
CPU: 0 PID: 13779 Comm: syz-executor2 Not tainted 5.0.0-rc4-next-20190131 #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_bad_irq_dependency kernel/locking/lockdep.c:1573 [inline]
 check_usage.cold+0x60f/0x940 kernel/locking/lockdep.c:1605
 check_irq_usage kernel/locking/lockdep.c:1650 [inline]
 check_prev_add_irq kernel/locking/lockdep_states.h:8 [inline]
 check_prev_add kernel/locking/lockdep.c:1860 [inline]
 check_prevs_add kernel/locking/lockdep.c:1968 [inline]
 validate_chain kernel/locking/lockdep.c:2339 [inline]
 __lock_acquire+0x1f12/0x4790 kernel/locking/lockdep.c:3320
 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
 spin_lock include/linux/spinlock.h:329 [inline]
 aio_poll fs/aio.c:1772 [inline]
 __io_submit_one fs/aio.c:1875 [inline]
 io_submit_one+0xedf/0x1cf0 fs/aio.c:1908
 __do_sys_io_submit fs/aio.c:1953 [inline]
 __se_sys_io_submit fs/aio.c:1923 [inline]
 __x64_sys_io_submit+0x1bd/0x580 fs/aio.c:1923
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reported-by: syzbot <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Avi Kivity <[email protected]>
Cc: Miklos Szeredi <[email protected]>
Cc: <[email protected]>
Fixes: e8693bc ("aio: allow direct aio poll comletions for keyed wakeups") # v4.19
Signed-off-by: Miklos Szeredi <[email protected]>
[ bvanassche: added a comment ]
Reluctantly-Acked-by: Christoph Hellwig <[email protected]>
Signed-off-by: Bart Van Assche <[email protected]>
Signed-off-by: Al Viro <[email protected]>
dabrace pushed a commit that referenced this pull request Aug 9, 2019
A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <[email protected]>
Cc: [email protected]
Signed-off-by: Jens Axboe <[email protected]>
dabrace pushed a commit that referenced this pull request Aug 12, 2019
syzbot reported the following crash [0]:

BUG: KASAN: use-after-free in usb_free_coherent+0x79/0x80
drivers/usb/core/usb.c:928
Read of size 8 at addr ffff8881b18599c8 by task syz-executor.4/16007

CPU: 0 PID: 16007 Comm: syz-executor.4 Not tainted 5.3.0-rc2+ #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0xca/0x13e lib/dump_stack.c:113
  print_address_description+0x6a/0x32c mm/kasan/report.c:351
  __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482
  kasan_report+0xe/0x12 mm/kasan/common.c:612
  usb_free_coherent+0x79/0x80 drivers/usb/core/usb.c:928
  yurex_delete+0x138/0x330 drivers/usb/misc/yurex.c:100
  kref_put include/linux/kref.h:65 [inline]
  yurex_release+0x66/0x90 drivers/usb/misc/yurex.c:392
  __fput+0x2d7/0x840 fs/file_table.c:280
  task_work_run+0x13f/0x1c0 kernel/task_work.c:113
  tracehook_notify_resume include/linux/tracehook.h:188 [inline]
  exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:163
  prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
  syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
  do_syscall_64+0x45f/0x580 arch/x86/entry/common.c:299
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x413511
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48
83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48
89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffc424ea2e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000413511
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 0000000000000001 R08: 0000000029a2fc22 R09: 0000000029a2fc26
R10: 00007ffc424ea3c0 R11: 0000000000000293 R12: 000000000075c9a0
R13: 000000000075c9a0 R14: 0000000000761938 R15: ffffffffffffffff

Allocated by task 2776:
  save_stack+0x1b/0x80 mm/kasan/common.c:69
  set_track mm/kasan/common.c:77 [inline]
  __kasan_kmalloc mm/kasan/common.c:487 [inline]
  __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:460
  kmalloc include/linux/slab.h:552 [inline]
  kzalloc include/linux/slab.h:748 [inline]
  usb_alloc_dev+0x51/0xf95 drivers/usb/core/usb.c:583
  hub_port_connect drivers/usb/core/hub.c:5004 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
  port_event drivers/usb/core/hub.c:5359 [inline]
  hub_event+0x15c0/0x3640 drivers/usb/core/hub.c:5441
  process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
  worker_thread+0x96/0xe20 kernel/workqueue.c:2415
  kthread+0x318/0x420 kernel/kthread.c:255
  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 16007:
  save_stack+0x1b/0x80 mm/kasan/common.c:69
  set_track mm/kasan/common.c:77 [inline]
  __kasan_slab_free+0x130/0x180 mm/kasan/common.c:449
  slab_free_hook mm/slub.c:1423 [inline]
  slab_free_freelist_hook mm/slub.c:1470 [inline]
  slab_free mm/slub.c:3012 [inline]
  kfree+0xe4/0x2f0 mm/slub.c:3953
  device_release+0x71/0x200 drivers/base/core.c:1064
  kobject_cleanup lib/kobject.c:693 [inline]
  kobject_release lib/kobject.c:722 [inline]
  kref_put include/linux/kref.h:65 [inline]
  kobject_put+0x171/0x280 lib/kobject.c:739
  put_device+0x1b/0x30 drivers/base/core.c:2213
  usb_put_dev+0x1f/0x30 drivers/usb/core/usb.c:725
  yurex_delete+0x40/0x330 drivers/usb/misc/yurex.c:95
  kref_put include/linux/kref.h:65 [inline]
  yurex_release+0x66/0x90 drivers/usb/misc/yurex.c:392
  __fput+0x2d7/0x840 fs/file_table.c:280
  task_work_run+0x13f/0x1c0 kernel/task_work.c:113
  tracehook_notify_resume include/linux/tracehook.h:188 [inline]
  exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:163
  prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
  syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
  do_syscall_64+0x45f/0x580 arch/x86/entry/common.c:299
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8881b1859980
  which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 72 bytes inside of
  2048-byte region [ffff8881b1859980, ffff8881b185a180)
The buggy address belongs to the page:
page:ffffea0006c61600 refcount:1 mapcount:0 mapping:ffff8881da00c000
index:0x0 compound_mapcount: 0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 0000000000000000 0000000100000001 ffff8881da00c000
raw: 0000000000000000 00000000000f000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8881b1859880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff8881b1859900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff8881b1859980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                               ^
  ffff8881b1859a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8881b1859a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

A quick look at the yurex_delete() shows that we drop the reference
to the usb_device before releasing any buffers associated with the
device. Delay the reference drop until we have finished the cleanup.

[0] https://lore.kernel.org/lkml/[email protected]/

Fixes: 6bc235a ("USB: add driver for Meywa-Denki & Kayac YUREX")
Cc: Jiri Kosina <[email protected]>
Cc: Tomoki Sekiyama <[email protected]>
Cc: Oliver Neukum <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Alan Stern <[email protected]>
Cc: [email protected]
Cc: [email protected]
Reported-by: [email protected]
Signed-off-by: Suzuki K Poulose <[email protected]>
Cc: stable <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
dabrace pushed a commit that referenced this pull request Nov 11, 2019
Turns out hotplugging CPUs that are in exclusive cpusets can lead to the
cpuset code feeding empty cpumasks to the sched domain rebuild machinery.

This leads to the following splat:

    Internal error: Oops: 96000004 [#1] PREEMPT SMP
    Modules linked in:
    CPU: 0 PID: 235 Comm: kworker/5:2 Not tainted 5.4.0-rc1-00005-g8d495477d62e #23
    Hardware name: ARM Juno development board (r0) (DT)
    Workqueue: events cpuset_hotplug_workfn
    pstate: 60000005 (nZCv daif -PAN -UAO)
    pc : build_sched_domains (./include/linux/arch_topology.h:23 kernel/sched/topology.c:1898 kernel/sched/topology.c:1969)
    lr : build_sched_domains (kernel/sched/topology.c:1966)
    Call trace:
    build_sched_domains (./include/linux/arch_topology.h:23 kernel/sched/topology.c:1898 kernel/sched/topology.c:1969)
    partition_sched_domains_locked (kernel/sched/topology.c:2250)
    rebuild_sched_domains_locked (./include/linux/bitmap.h:370 ./include/linux/cpumask.h:538 kernel/cgroup/cpuset.c:955 kernel/cgroup/cpuset.c:978 kernel/cgroup/cpuset.c:1019)
    rebuild_sched_domains (kernel/cgroup/cpuset.c:1032)
    cpuset_hotplug_workfn (kernel/cgroup/cpuset.c:3205 (discriminator 2))
    process_one_work (./arch/arm64/include/asm/jump_label.h:21 ./include/linux/jump_label.h:200 ./include/trace/events/workqueue.h:114 kernel/workqueue.c:2274)
    worker_thread (./include/linux/compiler.h:199 ./include/linux/list.h:268 kernel/workqueue.c:2416)
    kthread (kernel/kthread.c:255)
    ret_from_fork (arch/arm64/kernel/entry.S:1167)
    Code: f860dae2 912802d6 aa1603e1 12800000 (f8616853)

The faulty line in question is:

  cap = arch_scale_cpu_capacity(cpumask_first(cpu_map));

and we're not checking the return value against nr_cpu_ids (we shouldn't
have to!), which leads to the above.

Prevent generate_sched_domains() from returning empty cpumasks, and add
some assertion in build_sched_domains() to scream bloody murder if it
happens again.

The above splat was obtained on my Juno r0 with the following reproducer:

  $ cgcreate -g cpuset:asym
  $ cgset -r cpuset.cpus=0-3 asym
  $ cgset -r cpuset.mems=0 asym
  $ cgset -r cpuset.cpu_exclusive=1 asym

  $ cgcreate -g cpuset:smp
  $ cgset -r cpuset.cpus=4-5 smp
  $ cgset -r cpuset.mems=0 smp
  $ cgset -r cpuset.cpu_exclusive=1 smp

  $ cgset -r cpuset.sched_load_balance=0 .

  $ echo 0 > /sys/devices/system/cpu/cpu4/online
  $ echo 0 > /sys/devices/system/cpu/cpu5/online

Signed-off-by: Valentin Schneider <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: [email protected]
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Fixes: 05484e0 ("sched/topology: Add SD_ASYM_CPUCAPACITY flag detection")
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
dabrace pushed a commit that referenced this pull request Jan 13, 2020
Before commit 4bfc0bb ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself")
cgroup bpf structures were released with
corresponding cgroup structures. It guaranteed the hierarchical order
of destruction: children were always first. It preserved attached
programs from being released before their propagated copies.

But with cgroup auto-detachment there are no such guarantees anymore:
cgroup bpf is released as soon as the cgroup is offline and there are
no live associated sockets. It means that an attached program can be
detached and released, while its propagated copy is still living
in the cgroup subtree. This will obviously lead to an use-after-free
bug.

To reproduce the issue the following script can be used:

  #!/bin/bash

  CGROOT=/sys/fs/cgroup

  mkdir -p ${CGROOT}/A ${CGROOT}/B ${CGROOT}/A/C
  sleep 1

  ./test_cgrp2_attach ${CGROOT}/A egress &
  A_PID=$!
  ./test_cgrp2_attach ${CGROOT}/B egress &
  B_PID=$!

  echo $$ > ${CGROOT}/A/C/cgroup.procs
  iperf -s &
  S_PID=$!
  iperf -c localhost -t 100 &
  C_PID=$!

  sleep 1

  echo $$ > ${CGROOT}/B/cgroup.procs
  echo ${S_PID} > ${CGROOT}/B/cgroup.procs
  echo ${C_PID} > ${CGROOT}/B/cgroup.procs

  sleep 1

  rmdir ${CGROOT}/A/C
  rmdir ${CGROOT}/A

  sleep 1

  kill -9 ${S_PID} ${C_PID} ${A_PID} ${B_PID}

On the unpatched kernel the following stacktrace can be obtained:

[   33.619799] BUG: unable to handle page fault for address: ffffbdb4801ab002
[   33.620677] #PF: supervisor read access in kernel mode
[   33.621293] #PF: error_code(0x0000) - not-present page
[   33.622754] Oops: 0000 [#1] SMP NOPTI
[   33.623202] CPU: 0 PID: 601 Comm: iperf Not tainted 5.5.0-rc2+ #23
[   33.625545] RIP: 0010:__cgroup_bpf_run_filter_skb+0x29f/0x3d0
[   33.635809] Call Trace:
[   33.636118]  ? __cgroup_bpf_run_filter_skb+0x2bf/0x3d0
[   33.636728]  ? __switch_to_asm+0x40/0x70
[   33.637196]  ip_finish_output+0x68/0xa0
[   33.637654]  ip_output+0x76/0xf0
[   33.638046]  ? __ip_finish_output+0x1c0/0x1c0
[   33.638576]  __ip_queue_xmit+0x157/0x410
[   33.639049]  __tcp_transmit_skb+0x535/0xaf0
[   33.639557]  tcp_write_xmit+0x378/0x1190
[   33.640049]  ? _copy_from_iter_full+0x8d/0x260
[   33.640592]  tcp_sendmsg_locked+0x2a2/0xdc0
[   33.641098]  ? sock_has_perm+0x10/0xa0
[   33.641574]  tcp_sendmsg+0x28/0x40
[   33.641985]  sock_sendmsg+0x57/0x60
[   33.642411]  sock_write_iter+0x97/0x100
[   33.642876]  new_sync_write+0x1b6/0x1d0
[   33.643339]  vfs_write+0xb6/0x1a0
[   33.643752]  ksys_write+0xa7/0xe0
[   33.644156]  do_syscall_64+0x5b/0x1b0
[   33.644605]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix this by grabbing a reference to the bpf structure of each ancestor
on the initialization of the cgroup bpf structure, and dropping the
reference at the end of releasing the cgroup bpf structure.

This will restore the hierarchical order of cgroup bpf releasing,
without adding any operations on hot paths.

Thanks to Josef Bacik for the debugging and the initial analysis of
the problem.

Fixes: 4bfc0bb ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself")
Reported-by: Josef Bacik <[email protected]>
Signed-off-by: Roman Gushchin <[email protected]>
Acked-by: Song Liu <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
dabrace pushed a commit that referenced this pull request Aug 14, 2020
This patch is to fix a crash:

 #3 [ffffb6580689f898] oops_end at ffffffffa2835bc2
 #4 [ffffb6580689f8b8] no_context at ffffffffa28766e7
 #5 [ffffb6580689f920] async_page_fault at ffffffffa320135e
    [exception RIP: f2fs_is_compressed_page+34]
    RIP: ffffffffa2ba83a2  RSP: ffffb6580689f9d8  RFLAGS: 00010213
    RAX: 0000000000000001  RBX: fffffc0f50b34bc0  RCX: 0000000000002122
    RDX: 0000000000002123  RSI: 0000000000000c00  RDI: fffffc0f50b34bc0
    RBP: ffff97e815a40178   R8: 0000000000000000   R9: ffff97e83ffc9000
    R10: 0000000000032300  R11: 0000000000032380  R12: ffffb6580689fa38
    R13: fffffc0f50b34bc0  R14: ffff97e825cbd000  R15: 0000000000000c00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #6 [ffffb6580689f9d8] __is_cp_guaranteed at ffffffffa2b7ea98
 #7 [ffffb6580689f9f0] f2fs_submit_page_write at ffffffffa2b81a69
 #8 [ffffb6580689fa30] f2fs_do_write_meta_page at ffffffffa2b99777
 #9 [ffffb6580689fae0] __f2fs_write_meta_page at ffffffffa2b75f1a
 #10 [ffffb6580689fb18] f2fs_sync_meta_pages at ffffffffa2b77466
 #11 [ffffb6580689fc98] do_checkpoint at ffffffffa2b78e46
 #12 [ffffb6580689fd88] f2fs_write_checkpoint at ffffffffa2b79c29
 #13 [ffffb6580689fdd0] f2fs_sync_fs at ffffffffa2b69d95
 #14 [ffffb6580689fe20] sync_filesystem at ffffffffa2ad2574
 #15 [ffffb6580689fe30] generic_shutdown_super at ffffffffa2a9b582
 #16 [ffffb6580689fe48] kill_block_super at ffffffffa2a9b6d1
 #17 [ffffb6580689fe60] kill_f2fs_super at ffffffffa2b6abe1
 #18 [ffffb6580689fea0] deactivate_locked_super at ffffffffa2a9afb6
 #19 [ffffb6580689feb8] cleanup_mnt at ffffffffa2abcad4
 #20 [ffffb6580689fee0] task_work_run at ffffffffa28bca28
 #21 [ffffb6580689ff00] exit_to_usermode_loop at ffffffffa28050b7
 #22 [ffffb6580689ff38] do_syscall_64 at ffffffffa280560e
 #23 [ffffb6580689ff50] entry_SYSCALL_64_after_hwframe at ffffffffa320008c

This occurred when umount f2fs if enable F2FS_FS_COMPRESSION
with F2FS_IO_TRACE. Fixes it by adding IS_IO_TRACED_PAGE to check
validity of pid for page_private.

Signed-off-by: Yu Changchun <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
dabrace pushed a commit that referenced this pull request Nov 9, 2020
The atomic check hooks must look up the encoder to be used with a
connector from the connector's atomic state, and not assume that it's
the connector's current attached encoder. The latter one can change
under the atomic check func, or can be unset yet as in the case of MST
connectors.

This fixes
[    7.940719] Oops: 0000 [#1] SMP NOPTI
[    7.944407] CPU: 2 PID: 143 Comm: kworker/2:2 Not tainted 5.6.0-1023-oem #23-Ubuntu
[    7.952102] Hardware name: Dell Inc. Latitude 7320/, BIOS 88.87.11 09/07/2020
[    7.959278] Workqueue: events output_poll_execute [drm_kms_helper]
[    7.965511] RIP: 0010:intel_psr_atomic_check+0x37/0xa0 [i915]
[    7.971327] Code: 80 2d 06 00 00 20 74 42 80 b8 34 71 00 00 00 74 39 48 8b 72 08 48 85 f6 74 30 80 b8 f8 71 00 00 00 74 27 4c 8b 87 80 04 00 00 <41> 8b 78 78 83 ff 08 77 19 31 c9 83 ff 05 77 19 48 81 c1 20 01 00
[    7.977541] input: PS/2 Generic Mouse as /devices/platform/i8042/serio1/input/input5
[    7.990154] RSP: 0018:ffffb864c073fac8 EFLAGS: 00010202
[    7.990155] RAX: ffff8c5d55ce0000 RBX: ffff8c5d54519000 RCX: 0000000000000000
[    7.990155] RDX: ffff8c5d55cb30c0 RSI: ffff8c5d89a0c800 RDI: ffff8c5d55fcf800
[    7.990156] RBP: ffffb864c073fac8 R08: 0000000000000000 R09: ffff8c5d55d9f3a0
[    7.990156] R10: ffff8c5d55cb30c0 R11: 0000000000000009 R12: ffff8c5d55fcf800
[    7.990156] R13: ffff8c5d55cb30c0 R14: ffff8c5d56989cc0 R15: ffff8c5d56989cc0
[    7.990158] FS:  0000000000000000(0000) GS:ffff8c5d8e480000(0000) knlGS:0000000000000000
[    8.047193] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    8.052970] CR2: 0000000000000078 CR3: 0000000856500005 CR4: 0000000000760ee0
[    8.060137] PKRU: 55555554
[    8.062867] Call Trace:
[    8.065361]  intel_digital_connector_atomic_check+0x53/0x130 [i915]
[    8.071703]  intel_dp_mst_atomic_check+0x5b/0x200 [i915]
[    8.077074]  drm_atomic_helper_check_modeset+0x1db/0x790 [drm_kms_helper]
[    8.083942]  intel_atomic_check+0x92/0xc50 [i915]
[    8.088705]  ? drm_plane_check_pixel_format+0x4f/0xb0 [drm]
[    8.094345]  ? drm_atomic_plane_check+0x7a/0x3a0 [drm]
[    8.099548]  drm_atomic_check_only+0x2b1/0x450 [drm]
[    8.104573]  drm_atomic_commit+0x18/0x50 [drm]
[    8.109070]  drm_client_modeset_commit_atomic+0x1c9/0x200 [drm]
[    8.115056]  drm_client_modeset_commit_force+0x55/0x160 [drm]
[    8.120866]  drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xb0 [drm_kms_helper]
[    8.128415]  drm_fb_helper_set_par+0x34/0x50 [drm_kms_helper]
[    8.134225]  drm_fb_helper_hotplug_event.part.0+0xb4/0xe0 [drm_kms_helper]
[    8.141150]  drm_fb_helper_hotplug_event+0x1c/0x30 [drm_kms_helper]
[    8.147481]  intel_fbdev_output_poll_changed+0x6f/0xa0 [i915]
[    8.153287]  drm_kms_helper_hotplug_event+0x2c/0x40 [drm_kms_helper]
[    8.159709]  output_poll_execute+0x1aa/0x1c0 [drm_kms_helper]
[    8.165506]  process_one_work+0x1e8/0x3b0
[    8.169561]  worker_thread+0x4d/0x400
[    8.173249]  kthread+0x104/0x140
[    8.176515]  ? process_one_work+0x3b0/0x3b0
[    8.180726]  ? kthread_park+0x90/0x90
[    8.184416]  ret_from_fork+0x1f/0x40

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2361
References: https://gitlab.freedesktop.org/drm/intel/-/issues/2486
Reported-by: William Tseng <[email protected]>
Reported-by: Cooper Chiou <[email protected]>
Cc: <[email protected]>
Signed-off-by: Imre Deak <[email protected]>
Reviewed-by: Anshuman Gupta <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
(cherry picked from commit 00e5deb)
Signed-off-by: Rodrigo Vivi <[email protected]>
dabrace pushed a commit that referenced this pull request Nov 23, 2020
This fix is for a failure that occurred in the DWARF unwind perf test.

Stack unwinders may probe memory when looking for frames.

Memory sanitizer will poison and track uninitialized memory on the
stack, and on the heap if the value is copied to the heap.

This can lead to false memory sanitizer failures for the use of an
uninitialized value.

Avoid this problem by removing the poison on the copied stack.

The full msan failure with track origins looks like:

==2168==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22
    #1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13
    #2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #24 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10
    #1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13
    #2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18
    #3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #25 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3
    #1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2
    #2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9
    #3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6
    #4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #17 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events'
    #0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445

SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi
Signed-off-by: Ian Rogers <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: [email protected]
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sandeep Dasgupta <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
dabrace pushed a commit that referenced this pull request Jan 25, 2021
Zygo reported the following KASAN splat:

  BUG: KASAN: use-after-free in btrfs_backref_cleanup_node+0x18a/0x420
  Read of size 8 at addr ffff888112402950 by task btrfs/28836

  CPU: 0 PID: 28836 Comm: btrfs Tainted: G        W         5.10.0-e35f27394290-for-next+ #23
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  Call Trace:
   dump_stack+0xbc/0xf9
   ? btrfs_backref_cleanup_node+0x18a/0x420
   print_address_description.constprop.8+0x21/0x210
   ? record_print_text.cold.34+0x11/0x11
   ? btrfs_backref_cleanup_node+0x18a/0x420
   ? btrfs_backref_cleanup_node+0x18a/0x420
   kasan_report.cold.10+0x20/0x37
   ? btrfs_backref_cleanup_node+0x18a/0x420
   __asan_load8+0x69/0x90
   btrfs_backref_cleanup_node+0x18a/0x420
   btrfs_backref_release_cache+0x83/0x1b0
   relocate_block_group+0x394/0x780
   ? merge_reloc_roots+0x4a0/0x4a0
   btrfs_relocate_block_group+0x26e/0x4c0
   btrfs_relocate_chunk+0x52/0x120
   btrfs_balance+0xe2e/0x1900
   ? check_flags.part.50+0x6c/0x1e0
   ? btrfs_relocate_chunk+0x120/0x120
   ? kmem_cache_alloc_trace+0xa06/0xcb0
   ? _copy_from_user+0x83/0xc0
   btrfs_ioctl_balance+0x3a7/0x460
   btrfs_ioctl+0x24c8/0x4360
   ? __kasan_check_read+0x11/0x20
   ? check_chain_key+0x1f4/0x2f0
   ? __asan_loadN+0xf/0x20
   ? btrfs_ioctl_get_supported_features+0x30/0x30
   ? kvm_sched_clock_read+0x18/0x30
   ? check_chain_key+0x1f4/0x2f0
   ? lock_downgrade+0x3f0/0x3f0
   ? handle_mm_fault+0xad6/0x2150
   ? do_vfs_ioctl+0xfc/0x9d0
   ? ioctl_file_clone+0xe0/0xe0
   ? check_flags.part.50+0x6c/0x1e0
   ? check_flags.part.50+0x6c/0x1e0
   ? check_flags+0x26/0x30
   ? lock_is_held_type+0xc3/0xf0
   ? syscall_enter_from_user_mode+0x1b/0x60
   ? do_syscall_64+0x13/0x80
   ? rcu_read_lock_sched_held+0xa1/0xd0
   ? __kasan_check_read+0x11/0x20
   ? __fget_light+0xae/0x110
   __x64_sys_ioctl+0xc3/0x100
   do_syscall_64+0x37/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f4c4bdfe427

  Allocated by task 28836:
   kasan_save_stack+0x21/0x50
   __kasan_kmalloc.constprop.18+0xbe/0xd0
   kasan_kmalloc+0x9/0x10
   kmem_cache_alloc_trace+0x410/0xcb0
   btrfs_backref_alloc_node+0x46/0xf0
   btrfs_backref_add_tree_node+0x60d/0x11d0
   build_backref_tree+0xc5/0x700
   relocate_tree_blocks+0x2be/0xb90
   relocate_block_group+0x2eb/0x780
   btrfs_relocate_block_group+0x26e/0x4c0
   btrfs_relocate_chunk+0x52/0x120
   btrfs_balance+0xe2e/0x1900
   btrfs_ioctl_balance+0x3a7/0x460
   btrfs_ioctl+0x24c8/0x4360
   __x64_sys_ioctl+0xc3/0x100
   do_syscall_64+0x37/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

  Freed by task 28836:
   kasan_save_stack+0x21/0x50
   kasan_set_track+0x20/0x30
   kasan_set_free_info+0x1f/0x30
   __kasan_slab_free+0xf3/0x140
   kasan_slab_free+0xe/0x10
   kfree+0xde/0x200
   btrfs_backref_error_cleanup+0x452/0x530
   build_backref_tree+0x1a5/0x700
   relocate_tree_blocks+0x2be/0xb90
   relocate_block_group+0x2eb/0x780
   btrfs_relocate_block_group+0x26e/0x4c0
   btrfs_relocate_chunk+0x52/0x120
   btrfs_balance+0xe2e/0x1900
   btrfs_ioctl_balance+0x3a7/0x460
   btrfs_ioctl+0x24c8/0x4360
   __x64_sys_ioctl+0xc3/0x100
   do_syscall_64+0x37/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

This occurred because we freed our backref node in
btrfs_backref_error_cleanup(), but then tried to free it again in
btrfs_backref_release_cache().  This is because
btrfs_backref_release_cache() will cycle through all of the
cache->leaves nodes and free them up.  However
btrfs_backref_error_cleanup() freed the backref node with
btrfs_backref_free_node(), which simply kfree()d the backref node
without unlinking it from the cache.  Change this to a
btrfs_backref_drop_node(), which does the appropriate cleanup and
removes the node from the cache->leaves list, so when we go to free the
remaining cache we don't trip over items we've already dropped.

Fixes: 75bfb9a ("Btrfs: cleanup error handling in build_backref_tree")
CC: [email protected] # 4.4+
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
dabrace pushed a commit that referenced this pull request Mar 17, 2022
When bringing down the netdevice or system shutdown, a panic can be
triggered while accessing the sysfs path because the device is already
removed.

    [  755.549084] mlx5_core 0000:12:00.1: Shutdown was called
    [  756.404455] mlx5_core 0000:12:00.0: Shutdown was called
    ...
    [  757.937260] BUG: unable to handle kernel NULL pointer dereference at           (null)
    [  758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280

    crash> bt
    ...
    PID: 12649  TASK: ffff8924108f2100  CPU: 1   COMMAND: "amsd"
    ...
     #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778
        [exception RIP: dma_pool_alloc+0x1ab]
        RIP: ffffffff8ee11acb  RSP: ffff89240e1a3968  RFLAGS: 00010046
        RAX: 0000000000000246  RBX: ffff89243d874100  RCX: 0000000000001000
        RDX: 0000000000000000  RSI: 0000000000000246  RDI: ffff89243d874090
        RBP: ffff89240e1a39c0   R8: 000000000001f080   R9: ffff8905ffc03c00
        R10: ffffffffc04680d4  R11: ffffffff8edde9fd  R12: 00000000000080d0
        R13: ffff89243d874090  R14: ffff89243d874080  R15: 0000000000000000
        ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core]
    #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core]
    #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core]
    #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core]
    #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core]
    #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core]
    #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core]
    #17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46
    #18 [ffff89240e1a3d48] speed_show at ffffffff8f277208
    #19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3
    #20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf
    #21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596
    #22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10
    #23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5
    #24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff
    #25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f
    #26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92

    crash> net_device.state ffff89443b0c0000
      state = 0x5  (__LINK_STATE_START| __LINK_STATE_NOCARRIER)

To prevent this scenario, we also make sure that the netdevice is present.

Signed-off-by: suresh kumar <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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