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[bcm2708_fb] wrong physical screen dimension info? #65

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maxnet opened this issue Jul 24, 2012 · 2 comments
Closed

[bcm2708_fb] wrong physical screen dimension info? #65

maxnet opened this issue Jul 24, 2012 · 2 comments

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@maxnet
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maxnet commented Jul 24, 2012

I am getting very small unreadable fonts displayed in an application that uses the Qt 4 Embedded library (which uses the framebuffer directly, instead of standard Qt that uses X).
This seems to be caused by the framebuffer module advertising wrong physical screen dimensions, which I suspect the library uses to do some kind of DPI/font size calculation.

in bcm2708_fb_register() you have:

fb->fb.var.height = fbwidth;
fb->fb.var.width = fbheight;

Besides width and height being swapped, it seems those fields are meant to be filled in with the physical size of the display in mm:

__u32 height;           /* height of picture in mm    */
__u32 width;            /* width of picture in mm     */

My application does work properly if I change the code to:

fb->fb.var.height = -1;
fb->fb.var.width = -1;

to match what the vesafb driver is setting to indicate it doesn't know the size.

@popcornmix
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This should be fixed now. Can you test and close?

@maxnet
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maxnet commented Jul 27, 2012

Thanks. Works.

@maxnet maxnet closed this as completed Jul 27, 2012
bmwiedemann pushed a commit to bmwiedemann/raspberrypi-linux that referenced this issue Aug 8, 2012
popcornmix pushed a commit that referenced this issue Mar 28, 2013
[ Upstream commit ece6b0a ]

Dave Jones reported the following bug:

"When fed mangled socket data, rds will trust what userspace gives it,
and tries to allocate enormous amounts of memory larger than what
kmalloc can satisfy."

WARNING: at mm/page_alloc.c:2393 __alloc_pages_nodemask+0xa0d/0xbe0()
Hardware name: GA-MA78GM-S2H
Modules linked in: vmw_vsock_vmci_transport vmw_vmci vsock fuse bnep dlci bridge 8021q garp stp mrp binfmt_misc l2tp_ppp l2tp_core rfcomm s
Pid: 24652, comm: trinity-child2 Not tainted 3.8.0+ #65
Call Trace:
 [<ffffffff81044155>] warn_slowpath_common+0x75/0xa0
 [<ffffffff8104419a>] warn_slowpath_null+0x1a/0x20
 [<ffffffff811444ad>] __alloc_pages_nodemask+0xa0d/0xbe0
 [<ffffffff8100a196>] ? native_sched_clock+0x26/0x90
 [<ffffffff810b2128>] ? trace_hardirqs_off_caller+0x28/0xc0
 [<ffffffff810b21cd>] ? trace_hardirqs_off+0xd/0x10
 [<ffffffff811861f8>] alloc_pages_current+0xb8/0x180
 [<ffffffff8113eaaa>] __get_free_pages+0x2a/0x80
 [<ffffffff811934fe>] kmalloc_order_trace+0x3e/0x1a0
 [<ffffffff81193955>] __kmalloc+0x2f5/0x3a0
 [<ffffffff8104df0c>] ? local_bh_enable_ip+0x7c/0xf0
 [<ffffffffa0401ab3>] rds_message_alloc+0x23/0xb0 [rds]
 [<ffffffffa04043a1>] rds_sendmsg+0x2b1/0x990 [rds]
 [<ffffffff810b21cd>] ? trace_hardirqs_off+0xd/0x10
 [<ffffffff81564620>] sock_sendmsg+0xb0/0xe0
 [<ffffffff810b2052>] ? get_lock_stats+0x22/0x70
 [<ffffffff810b24be>] ? put_lock_stats.isra.23+0xe/0x40
 [<ffffffff81567f30>] sys_sendto+0x130/0x180
 [<ffffffff810b872d>] ? trace_hardirqs_on+0xd/0x10
 [<ffffffff816c547b>] ? _raw_spin_unlock_irq+0x3b/0x60
 [<ffffffff816cd767>] ? sysret_check+0x1b/0x56
 [<ffffffff810b8695>] ? trace_hardirqs_on_caller+0x115/0x1a0
 [<ffffffff81341d8e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
 [<ffffffff816cd742>] system_call_fastpath+0x16/0x1b
---[ end trace eed6ae990d018c8b ]---

Reported-by: Dave Jones <[email protected]>
Cc: Dave Jones <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Venkat Venkatsubra <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Acked-by: Venkat Venkatsubra <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
popcornmix pushed a commit that referenced this issue Mar 31, 2014
When allocating RX buffers a fixed size is used, while freeing is based
on actually received bytes, resulting in the following kernel warning
when CONFIG_DMA_API_DEBUG is enabled:
 WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1051 check_unmap+0x258/0x894()
 macb e000b000.ethernet: DMA-API: device driver frees DMA memory with different size [device address=0x000000002d170040] [map size=1536 bytes] [unmap size=60 bytes]
 Modules linked in:
 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc3-xilinx-00220-g49f84081ce4f #65
 [<c001516c>] (unwind_backtrace) from [<c0011df8>] (show_stack+0x10/0x14)
 [<c0011df8>] (show_stack) from [<c03c775c>] (dump_stack+0x7c/0xc8)
 [<c03c775c>] (dump_stack) from [<c00245cc>] (warn_slowpath_common+0x60/0x84)
 [<c00245cc>] (warn_slowpath_common) from [<c0024670>] (warn_slowpath_fmt+0x2c/0x3c)
 [<c0024670>] (warn_slowpath_fmt) from [<c0227d44>] (check_unmap+0x258/0x894)
 [<c0227d44>] (check_unmap) from [<c0228588>] (debug_dma_unmap_page+0x64/0x70)
 [<c0228588>] (debug_dma_unmap_page) from [<c02ab78c>] (gem_rx+0x118/0x170)
 [<c02ab78c>] (gem_rx) from [<c02ac4d4>] (macb_poll+0x24/0x94)
 [<c02ac4d4>] (macb_poll) from [<c031222c>] (net_rx_action+0x6c/0x188)
 [<c031222c>] (net_rx_action) from [<c0028a28>] (__do_softirq+0x108/0x280)
 [<c0028a28>] (__do_softirq) from [<c0028e8c>] (irq_exit+0x84/0xf8)
 [<c0028e8c>] (irq_exit) from [<c000f360>] (handle_IRQ+0x68/0x8c)
 [<c000f360>] (handle_IRQ) from [<c0008528>] (gic_handle_irq+0x3c/0x60)
 [<c0008528>] (gic_handle_irq) from [<c0012904>] (__irq_svc+0x44/0x78)
 Exception stack(0xc056df20 to 0xc056df68)
 df20: 00000001 c0577430 00000000 c0577430 04ce8e0d 00000002 edfce238 00000000
 df40: 04e20f78 00000002 c05981f4 00000000 00000008 c056df68 c0064008 c02d7658
 df60: 20000013 ffffffff
 [<c0012904>] (__irq_svc) from [<c02d7658>] (cpuidle_enter_state+0x54/0xf8)
 [<c02d7658>] (cpuidle_enter_state) from [<c02d77dc>] (cpuidle_idle_call+0xe0/0x138)
 [<c02d77dc>] (cpuidle_idle_call) from [<c000f660>] (arch_cpu_idle+0x8/0x3c)
 [<c000f660>] (arch_cpu_idle) from [<c006bec4>] (cpu_startup_entry+0xbc/0x124)
 [<c006bec4>] (cpu_startup_entry) from [<c053daec>] (start_kernel+0x350/0x3b0)
 ---[ end trace d5fdc38641bd3a11 ]---
 Mapped at:
  [<c0227184>] debug_dma_map_page+0x48/0x11c
  [<c02ab32c>] gem_rx_refill+0x154/0x1f8
  [<c02ac7b4>] macb_open+0x270/0x3e0
  [<c03152e0>] __dev_open+0x7c/0xfc
  [<c031554c>] __dev_change_flags+0x8c/0x140

Fixing this by passing the same size which is passed during mapping the
memory to the unmap function as well.

Signed-off-by: Soren Brinkmann <[email protected]>
Reviewed-by: Ben Hutchings <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
anholt referenced this issue in anholt/linux Apr 21, 2015
A malicious signal handler / restorer can DOS the system by fudging the
user regs saved on stack, causing weird things such as sigreturn returning
to user mode PC but cpu state still being kernel mode....

Ensure that in sigreturn path status32 always has U bit; any other bogosity
(gargbage PC etc) will be taken care of by normal user mode exceptions mechanisms.

Reproducer signal handler:

    void handle_sig(int signo, siginfo_t *info, void *context)
    {
	ucontext_t *uc = context;
	struct user_regs_struct *regs = &(uc->uc_mcontext.regs);

	regs->scratch.status32 = 0;
    }

Before the fix, kernel would go off to weeds like below:

    --------->8-----------
    [ARCLinux]$ ./signal-test
    Path: /signal-test
    CPU: 0 PID: 61 Comm: signal-test Not tainted 4.0.0-rc5+ #65
    task: 8f177880 ti: 5ffe6000 task.ti: 8f15c000

    [ECR   ]: 0x00220200 => Invalid Write @ 0x00000010 by insn @ 0x00010698
    [EFA   ]: 0x00000010
    [BLINK ]: 0x2007c1ee
    [ERET  ]: 0x10698
    [STAT32]: 0x00000000 :                                   <--------
    BTA: 0x00010680	 SP: 0x5ffe7e48	 FP: 0x00000000
    LPS: 0x20003c6c	LPE: 0x20003c70	LPC: 0x00000000
    ...
    --------->8-----------

Reported-by: Alexey Brodkin <[email protected]>
Cc: <[email protected]>
Signed-off-by: Vineet Gupta <[email protected]>
popcornmix pushed a commit that referenced this issue May 9, 2015
[ Upstream commit e414081 ]

A malicious signal handler / restorer can DOS the system by fudging the
user regs saved on stack, causing weird things such as sigreturn returning
to user mode PC but cpu state still being kernel mode....

Ensure that in sigreturn path status32 always has U bit; any other bogosity
(gargbage PC etc) will be taken care of by normal user mode exceptions mechanisms.

Reproducer signal handler:

    void handle_sig(int signo, siginfo_t *info, void *context)
    {
	ucontext_t *uc = context;
	struct user_regs_struct *regs = &(uc->uc_mcontext.regs);

	regs->scratch.status32 = 0;
    }

Before the fix, kernel would go off to weeds like below:

    --------->8-----------
    [ARCLinux]$ ./signal-test
    Path: /signal-test
    CPU: 0 PID: 61 Comm: signal-test Not tainted 4.0.0-rc5+ #65
    task: 8f177880 ti: 5ffe6000 task.ti: 8f15c000

    [ECR   ]: 0x00220200 => Invalid Write @ 0x00000010 by insn @ 0x00010698
    [EFA   ]: 0x00000010
    [BLINK ]: 0x2007c1ee
    [ERET  ]: 0x10698
    [STAT32]: 0x00000000 :                                   <--------
    BTA: 0x00010680	 SP: 0x5ffe7e48	 FP: 0x00000000
    LPS: 0x20003c6c	LPE: 0x20003c70	LPC: 0x00000000
    ...
    --------->8-----------

Reported-by: Alexey Brodkin <[email protected]>
Cc: <[email protected]>
Signed-off-by: Vineet Gupta <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
syntheticpp pushed a commit to syntheticpp/linux that referenced this issue Jun 2, 2015
commit e414081 upstream.

A malicious signal handler / restorer can DOS the system by fudging the
user regs saved on stack, causing weird things such as sigreturn returning
to user mode PC but cpu state still being kernel mode....

Ensure that in sigreturn path status32 always has U bit; any other bogosity
(gargbage PC etc) will be taken care of by normal user mode exceptions mechanisms.

Reproducer signal handler:

    void handle_sig(int signo, siginfo_t *info, void *context)
    {
	ucontext_t *uc = context;
	struct user_regs_struct *regs = &(uc->uc_mcontext.regs);

	regs->scratch.status32 = 0;
    }

Before the fix, kernel would go off to weeds like below:

    --------->8-----------
    [ARCLinux]$ ./signal-test
    Path: /signal-test
    CPU: 0 PID: 61 Comm: signal-test Not tainted 4.0.0-rc5+ raspberrypi#65
    task: 8f177880 ti: 5ffe6000 task.ti: 8f15c000

    [ECR   ]: 0x00220200 => Invalid Write @ 0x00000010 by insn @ 0x00010698
    [EFA   ]: 0x00000010
    [BLINK ]: 0x2007c1ee
    [ERET  ]: 0x10698
    [STAT32]: 0x00000000 :                                   <--------
    BTA: 0x00010680	 SP: 0x5ffe7e48	 FP: 0x00000000
    LPS: 0x20003c6c	LPE: 0x20003c70	LPC: 0x00000000
    ...
    --------->8-----------

Reported-by: Alexey Brodkin <[email protected]>
Signed-off-by: Vineet Gupta <[email protected]>
Signed-off-by: Jiri Slaby <[email protected]>
popcornmix pushed a commit that referenced this issue Apr 11, 2016
When sending a UDPv6 message longer than MTU, account for the length
of fragmentable IPv6 extension headers in skb->network_header offset.
Same as we do in alloc_new_skb path in __ip6_append_data().

This ensures that later on __ip6_make_skb() will make space in
headroom for fragmentable extension headers:

	/* move skb->data to ip header from ext header */
	if (skb->data < skb_network_header(skb))
		__skb_pull(skb, skb_network_offset(skb));

Prevents a splat due to skb_under_panic:

skbuff: skb_under_panic: text:ffffffff8143397b len:2126 put:14 \
head:ffff880005bacf50 data:ffff880005bacf4a tail:0x48 end:0xc0 dev:lo
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:104!
invalid opcode: 0000 [#1] KASAN
CPU: 0 PID: 160 Comm: reproducer Not tainted 4.6.0-rc2 #65
[...]
Call Trace:
 [<ffffffff813eb7b9>] skb_push+0x79/0x80
 [<ffffffff8143397b>] eth_header+0x2b/0x100
 [<ffffffff8141e0d0>] neigh_resolve_output+0x210/0x310
 [<ffffffff814eab77>] ip6_finish_output2+0x4a7/0x7c0
 [<ffffffff814efe3a>] ip6_output+0x16a/0x280
 [<ffffffff815440c1>] ip6_local_out+0xb1/0xf0
 [<ffffffff814f1115>] ip6_send_skb+0x45/0xd0
 [<ffffffff81518836>] udp_v6_send_skb+0x246/0x5d0
 [<ffffffff8151985e>] udpv6_sendmsg+0xa6e/0x1090
[...]

Reported-by: Ji Jianwen <[email protected]>
Signed-off-by: Jakub Sitnicki <[email protected]>
Acked-by: Hannes Frederic Sowa <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
davet321 pushed a commit to davet321/rpi-linux that referenced this issue Apr 21, 2016
[ Upstream commit 3ba3458 ]

When sending a UDPv6 message longer than MTU, account for the length
of fragmentable IPv6 extension headers in skb->network_header offset.
Same as we do in alloc_new_skb path in __ip6_append_data().

This ensures that later on __ip6_make_skb() will make space in
headroom for fragmentable extension headers:

	/* move skb->data to ip header from ext header */
	if (skb->data < skb_network_header(skb))
		__skb_pull(skb, skb_network_offset(skb));

Prevents a splat due to skb_under_panic:

skbuff: skb_under_panic: text:ffffffff8143397b len:2126 put:14 \
head:ffff880005bacf50 data:ffff880005bacf4a tail:0x48 end:0xc0 dev:lo
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:104!
invalid opcode: 0000 [raspberrypi#1] KASAN
CPU: 0 PID: 160 Comm: reproducer Not tainted 4.6.0-rc2 raspberrypi#65
[...]
Call Trace:
 [<ffffffff813eb7b9>] skb_push+0x79/0x80
 [<ffffffff8143397b>] eth_header+0x2b/0x100
 [<ffffffff8141e0d0>] neigh_resolve_output+0x210/0x310
 [<ffffffff814eab77>] ip6_finish_output2+0x4a7/0x7c0
 [<ffffffff814efe3a>] ip6_output+0x16a/0x280
 [<ffffffff815440c1>] ip6_local_out+0xb1/0xf0
 [<ffffffff814f1115>] ip6_send_skb+0x45/0xd0
 [<ffffffff81518836>] udp_v6_send_skb+0x246/0x5d0
 [<ffffffff8151985e>] udpv6_sendmsg+0xa6e/0x1090
[...]

Reported-by: Ji Jianwen <[email protected]>
Signed-off-by: Jakub Sitnicki <[email protected]>
Acked-by: Hannes Frederic Sowa <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
popcornmix pushed a commit that referenced this issue Apr 22, 2016
[ Upstream commit 3ba3458 ]

When sending a UDPv6 message longer than MTU, account for the length
of fragmentable IPv6 extension headers in skb->network_header offset.
Same as we do in alloc_new_skb path in __ip6_append_data().

This ensures that later on __ip6_make_skb() will make space in
headroom for fragmentable extension headers:

	/* move skb->data to ip header from ext header */
	if (skb->data < skb_network_header(skb))
		__skb_pull(skb, skb_network_offset(skb));

Prevents a splat due to skb_under_panic:

skbuff: skb_under_panic: text:ffffffff8143397b len:2126 put:14 \
head:ffff880005bacf50 data:ffff880005bacf4a tail:0x48 end:0xc0 dev:lo
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:104!
invalid opcode: 0000 [#1] KASAN
CPU: 0 PID: 160 Comm: reproducer Not tainted 4.6.0-rc2 #65
[...]
Call Trace:
 [<ffffffff813eb7b9>] skb_push+0x79/0x80
 [<ffffffff8143397b>] eth_header+0x2b/0x100
 [<ffffffff8141e0d0>] neigh_resolve_output+0x210/0x310
 [<ffffffff814eab77>] ip6_finish_output2+0x4a7/0x7c0
 [<ffffffff814efe3a>] ip6_output+0x16a/0x280
 [<ffffffff815440c1>] ip6_local_out+0xb1/0xf0
 [<ffffffff814f1115>] ip6_send_skb+0x45/0xd0
 [<ffffffff81518836>] udp_v6_send_skb+0x246/0x5d0
 [<ffffffff8151985e>] udpv6_sendmsg+0xa6e/0x1090
[...]

Reported-by: Ji Jianwen <[email protected]>
Signed-off-by: Jakub Sitnicki <[email protected]>
Acked-by: Hannes Frederic Sowa <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
popcornmix pushed a commit that referenced this issue Mar 26, 2018
The l2tp_tunnel_create() function checks for v4mapped ipv6
sockets and cache that flag, so that l2tp core code can
reusing it at xmit time.

If the socket is provided by the userspace, the connection
status of the tunnel sockets can change between the tunnel
creation and the xmit call, so that syzbot is able to
trigger the following splat:

BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:192
[inline]
BUG: KASAN: use-after-free in ip6_xmit+0x1f76/0x2260
net/ipv6/ip6_output.c:264
Read of size 8 at addr ffff8801bd949318 by task syz-executor4/23448

CPU: 0 PID: 23448 Comm: syz-executor4 Not tainted 4.16.0-rc4+ #65
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x24d lib/dump_stack.c:53
  print_address_description+0x73/0x250 mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report+0x23c/0x360 mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  ip6_dst_idev include/net/ip6_fib.h:192 [inline]
  ip6_xmit+0x1f76/0x2260 net/ipv6/ip6_output.c:264
  inet6_csk_xmit+0x2fc/0x580 net/ipv6/inet6_connection_sock.c:139
  l2tp_xmit_core net/l2tp/l2tp_core.c:1053 [inline]
  l2tp_xmit_skb+0x105f/0x1410 net/l2tp/l2tp_core.c:1148
  pppol2tp_sendmsg+0x470/0x670 net/l2tp/l2tp_ppp.c:341
  sock_sendmsg_nosec net/socket.c:630 [inline]
  sock_sendmsg+0xca/0x110 net/socket.c:640
  ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046
  __sys_sendmsg+0xe5/0x210 net/socket.c:2080
  SYSC_sendmsg net/socket.c:2091 [inline]
  SyS_sendmsg+0x2d/0x50 net/socket.c:2087
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453e69
RSP: 002b:00007f819593cc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f819593d6d4 RCX: 0000000000453e69
RDX: 0000000000000081 RSI: 000000002037ffc8 RDI: 0000000000000004
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004c3 R14: 00000000006f72e8 R15: 0000000000000000

This change addresses the issues:
* explicitly checking for TCP_ESTABLISHED for user space provided sockets
* dropping the v4mapped flag usage - it can become outdated - and
  explicitly invoking ipv6_addr_v4mapped() instead

The issue is apparently there since ancient times.

v1 -> v2: (many thanks to Guillaume)
 - with csum issue introduced in v1
 - replace pr_err with pr_debug
 - fix build issue with IPV6 disabled
 - move l2tp_sk_is_v4mapped in l2tp_core.c

v2 -> v3:
 - don't update inet_daddr for v4mapped address, unneeded
 - drop rendundant check at creation time

Reported-and-tested-by: [email protected]
Fixes: 3557baa ("[L2TP]: PPP over L2TP driver core")
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
nathanchance pushed a commit to nathanchance/pi-kernel that referenced this issue Apr 8, 2018
commit b954f94 upstream.

The l2tp_tunnel_create() function checks for v4mapped ipv6
sockets and cache that flag, so that l2tp core code can
reusing it at xmit time.

If the socket is provided by the userspace, the connection
status of the tunnel sockets can change between the tunnel
creation and the xmit call, so that syzbot is able to
trigger the following splat:

BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:192
[inline]
BUG: KASAN: use-after-free in ip6_xmit+0x1f76/0x2260
net/ipv6/ip6_output.c:264
Read of size 8 at addr ffff8801bd949318 by task syz-executor4/23448

CPU: 0 PID: 23448 Comm: syz-executor4 Not tainted 4.16.0-rc4+ raspberrypi#65
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x24d lib/dump_stack.c:53
  print_address_description+0x73/0x250 mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report+0x23c/0x360 mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  ip6_dst_idev include/net/ip6_fib.h:192 [inline]
  ip6_xmit+0x1f76/0x2260 net/ipv6/ip6_output.c:264
  inet6_csk_xmit+0x2fc/0x580 net/ipv6/inet6_connection_sock.c:139
  l2tp_xmit_core net/l2tp/l2tp_core.c:1053 [inline]
  l2tp_xmit_skb+0x105f/0x1410 net/l2tp/l2tp_core.c:1148
  pppol2tp_sendmsg+0x470/0x670 net/l2tp/l2tp_ppp.c:341
  sock_sendmsg_nosec net/socket.c:630 [inline]
  sock_sendmsg+0xca/0x110 net/socket.c:640
  ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046
  __sys_sendmsg+0xe5/0x210 net/socket.c:2080
  SYSC_sendmsg net/socket.c:2091 [inline]
  SyS_sendmsg+0x2d/0x50 net/socket.c:2087
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453e69
RSP: 002b:00007f819593cc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f819593d6d4 RCX: 0000000000453e69
RDX: 0000000000000081 RSI: 000000002037ffc8 RDI: 0000000000000004
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004c3 R14: 00000000006f72e8 R15: 0000000000000000

This change addresses the issues:
* explicitly checking for TCP_ESTABLISHED for user space provided sockets
* dropping the v4mapped flag usage - it can become outdated - and
  explicitly invoking ipv6_addr_v4mapped() instead

The issue is apparently there since ancient times.

v1 -> v2: (many thanks to Guillaume)
 - with csum issue introduced in v1
 - replace pr_err with pr_debug
 - fix build issue with IPV6 disabled
 - move l2tp_sk_is_v4mapped in l2tp_core.c

v2 -> v3:
 - don't update inet_daddr for v4mapped address, unneeded
 - drop rendundant check at creation time

Reported-and-tested-by: [email protected]
Fixes: 3557baa ("[L2TP]: PPP over L2TP driver core")
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
popcornmix pushed a commit that referenced this issue Apr 9, 2018
commit b954f94 upstream.

The l2tp_tunnel_create() function checks for v4mapped ipv6
sockets and cache that flag, so that l2tp core code can
reusing it at xmit time.

If the socket is provided by the userspace, the connection
status of the tunnel sockets can change between the tunnel
creation and the xmit call, so that syzbot is able to
trigger the following splat:

BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:192
[inline]
BUG: KASAN: use-after-free in ip6_xmit+0x1f76/0x2260
net/ipv6/ip6_output.c:264
Read of size 8 at addr ffff8801bd949318 by task syz-executor4/23448

CPU: 0 PID: 23448 Comm: syz-executor4 Not tainted 4.16.0-rc4+ #65
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x24d lib/dump_stack.c:53
  print_address_description+0x73/0x250 mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report+0x23c/0x360 mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  ip6_dst_idev include/net/ip6_fib.h:192 [inline]
  ip6_xmit+0x1f76/0x2260 net/ipv6/ip6_output.c:264
  inet6_csk_xmit+0x2fc/0x580 net/ipv6/inet6_connection_sock.c:139
  l2tp_xmit_core net/l2tp/l2tp_core.c:1053 [inline]
  l2tp_xmit_skb+0x105f/0x1410 net/l2tp/l2tp_core.c:1148
  pppol2tp_sendmsg+0x470/0x670 net/l2tp/l2tp_ppp.c:341
  sock_sendmsg_nosec net/socket.c:630 [inline]
  sock_sendmsg+0xca/0x110 net/socket.c:640
  ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046
  __sys_sendmsg+0xe5/0x210 net/socket.c:2080
  SYSC_sendmsg net/socket.c:2091 [inline]
  SyS_sendmsg+0x2d/0x50 net/socket.c:2087
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453e69
RSP: 002b:00007f819593cc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f819593d6d4 RCX: 0000000000453e69
RDX: 0000000000000081 RSI: 000000002037ffc8 RDI: 0000000000000004
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004c3 R14: 00000000006f72e8 R15: 0000000000000000

This change addresses the issues:
* explicitly checking for TCP_ESTABLISHED for user space provided sockets
* dropping the v4mapped flag usage - it can become outdated - and
  explicitly invoking ipv6_addr_v4mapped() instead

The issue is apparently there since ancient times.

v1 -> v2: (many thanks to Guillaume)
 - with csum issue introduced in v1
 - replace pr_err with pr_debug
 - fix build issue with IPV6 disabled
 - move l2tp_sk_is_v4mapped in l2tp_core.c

v2 -> v3:
 - don't update inet_daddr for v4mapped address, unneeded
 - drop rendundant check at creation time

Reported-and-tested-by: [email protected]
Fixes: 3557baa ("[L2TP]: PPP over L2TP driver core")
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
popcornmix pushed a commit that referenced this issue Feb 26, 2019
The function prototype used to call JITed eBPF code (ie. the type of the
struct bpf_prog bpf_func field) returns an unsigned int. The MIPS n64
ABI that MIPS64 kernels target defines that 32 bit integers should
always be sign extended when passed in registers as either arguments or
return values.

This means that when returning any value which may not already be sign
extended (ie. of type REG_64BIT or REG_32BIT_ZERO_EX) we need to perform
that sign extension in order to comply with the n64 ABI. Without this we
see strange looking test failures from test_bpf.ko, such as:

  test_bpf: #65 ALU64_MOV_X:
    dst = 4294967295 jited:1 ret -1 != -1 FAIL (1 times)

Although the return value printed matches the expected value, this is
only because printf is only examining the least significant 32 bits of
the 64 bit register value we returned. The register holding the expected
value is sign extended whilst the v0 register was set to a zero extended
value by our JITed code, so when compared by a conditional branch
instruction the values are not equal.

We already handle this when the return value register is of type
REG_32BIT_ZERO_EX, so simply extend this to also cover REG_64BIT.

Signed-off-by: Paul Burton <[email protected]>
Fixes: b6bd53f ("MIPS: Add missing file for eBPF JIT.")
Cc: [email protected] # v4.13+
Signed-off-by: Daniel Borkmann <[email protected]>
popcornmix pushed a commit that referenced this issue Mar 6, 2019
commit 1344315 upstream.

The function prototype used to call JITed eBPF code (ie. the type of the
struct bpf_prog bpf_func field) returns an unsigned int. The MIPS n64
ABI that MIPS64 kernels target defines that 32 bit integers should
always be sign extended when passed in registers as either arguments or
return values.

This means that when returning any value which may not already be sign
extended (ie. of type REG_64BIT or REG_32BIT_ZERO_EX) we need to perform
that sign extension in order to comply with the n64 ABI. Without this we
see strange looking test failures from test_bpf.ko, such as:

  test_bpf: #65 ALU64_MOV_X:
    dst = 4294967295 jited:1 ret -1 != -1 FAIL (1 times)

Although the return value printed matches the expected value, this is
only because printf is only examining the least significant 32 bits of
the 64 bit register value we returned. The register holding the expected
value is sign extended whilst the v0 register was set to a zero extended
value by our JITed code, so when compared by a conditional branch
instruction the values are not equal.

We already handle this when the return value register is of type
REG_32BIT_ZERO_EX, so simply extend this to also cover REG_64BIT.

Signed-off-by: Paul Burton <[email protected]>
Fixes: b6bd53f ("MIPS: Add missing file for eBPF JIT.")
Cc: [email protected] # v4.13+
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
popcornmix pushed a commit that referenced this issue Mar 6, 2019
commit 1344315 upstream.

The function prototype used to call JITed eBPF code (ie. the type of the
struct bpf_prog bpf_func field) returns an unsigned int. The MIPS n64
ABI that MIPS64 kernels target defines that 32 bit integers should
always be sign extended when passed in registers as either arguments or
return values.

This means that when returning any value which may not already be sign
extended (ie. of type REG_64BIT or REG_32BIT_ZERO_EX) we need to perform
that sign extension in order to comply with the n64 ABI. Without this we
see strange looking test failures from test_bpf.ko, such as:

  test_bpf: #65 ALU64_MOV_X:
    dst = 4294967295 jited:1 ret -1 != -1 FAIL (1 times)

Although the return value printed matches the expected value, this is
only because printf is only examining the least significant 32 bits of
the 64 bit register value we returned. The register holding the expected
value is sign extended whilst the v0 register was set to a zero extended
value by our JITed code, so when compared by a conditional branch
instruction the values are not equal.

We already handle this when the return value register is of type
REG_32BIT_ZERO_EX, so simply extend this to also cover REG_64BIT.

Signed-off-by: Paul Burton <[email protected]>
Fixes: b6bd53f ("MIPS: Add missing file for eBPF JIT.")
Cc: [email protected] # v4.13+
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
popcornmix pushed a commit that referenced this issue Jul 31, 2019
[ Upstream commit 071c379 ]

Neigh timer can be scheduled multiple times from userspace adding
multiple neigh entries and forcing the neigh timer scheduling passing
NTF_USE in the netlink requests.
This will result in a refcount leak and in the following dump stack:

[   32.465295] NEIGH: BUG, double timer add, state is 8
[   32.465308] CPU: 0 PID: 416 Comm: double_timer_ad Not tainted 5.2.0+ #65
[   32.465311] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-2.fc30 04/01/2014
[   32.465313] Call Trace:
[   32.465318]  dump_stack+0x7c/0xc0
[   32.465323]  __neigh_event_send+0x20c/0x880
[   32.465326]  ? ___neigh_create+0x846/0xfb0
[   32.465329]  ? neigh_lookup+0x2a9/0x410
[   32.465332]  ? neightbl_fill_info.constprop.0+0x800/0x800
[   32.465334]  neigh_add+0x4f8/0x5e0
[   32.465337]  ? neigh_xmit+0x620/0x620
[   32.465341]  ? find_held_lock+0x85/0xa0
[   32.465345]  rtnetlink_rcv_msg+0x204/0x570
[   32.465348]  ? rtnl_dellink+0x450/0x450
[   32.465351]  ? mark_held_locks+0x90/0x90
[   32.465354]  ? match_held_lock+0x1b/0x230
[   32.465357]  netlink_rcv_skb+0xc4/0x1d0
[   32.465360]  ? rtnl_dellink+0x450/0x450
[   32.465363]  ? netlink_ack+0x420/0x420
[   32.465366]  ? netlink_deliver_tap+0x115/0x560
[   32.465369]  ? __alloc_skb+0xc9/0x2f0
[   32.465372]  netlink_unicast+0x270/0x330
[   32.465375]  ? netlink_attachskb+0x2f0/0x2f0
[   32.465378]  netlink_sendmsg+0x34f/0x5a0
[   32.465381]  ? netlink_unicast+0x330/0x330
[   32.465385]  ? move_addr_to_kernel.part.0+0x20/0x20
[   32.465388]  ? netlink_unicast+0x330/0x330
[   32.465391]  sock_sendmsg+0x91/0xa0
[   32.465394]  ___sys_sendmsg+0x407/0x480
[   32.465397]  ? copy_msghdr_from_user+0x200/0x200
[   32.465401]  ? _raw_spin_unlock_irqrestore+0x37/0x40
[   32.465404]  ? lockdep_hardirqs_on+0x17d/0x250
[   32.465407]  ? __wake_up_common_lock+0xcb/0x110
[   32.465410]  ? __wake_up_common+0x230/0x230
[   32.465413]  ? netlink_bind+0x3e1/0x490
[   32.465416]  ? netlink_setsockopt+0x540/0x540
[   32.465420]  ? __fget_light+0x9c/0xf0
[   32.465423]  ? sockfd_lookup_light+0x8c/0xb0
[   32.465426]  __sys_sendmsg+0xa5/0x110
[   32.465429]  ? __ia32_sys_shutdown+0x30/0x30
[   32.465432]  ? __fd_install+0xe1/0x2c0
[   32.465435]  ? lockdep_hardirqs_off+0xb5/0x100
[   32.465438]  ? mark_held_locks+0x24/0x90
[   32.465441]  ? do_syscall_64+0xf/0x270
[   32.465444]  do_syscall_64+0x63/0x270
[   32.465448]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fix the issue unscheduling neigh_timer if selected entry is in 'IN_TIMER'
receiving a netlink request with NTF_USE flag set

Reported-by: Marek Majkowski <[email protected]>
Fixes: 0c5c2d3 ("neigh: Allow for user space users of the neighbour table")
Signed-off-by: Lorenzo Bianconi <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
popcornmix pushed a commit that referenced this issue Jul 31, 2019
[ Upstream commit 071c379 ]

Neigh timer can be scheduled multiple times from userspace adding
multiple neigh entries and forcing the neigh timer scheduling passing
NTF_USE in the netlink requests.
This will result in a refcount leak and in the following dump stack:

[   32.465295] NEIGH: BUG, double timer add, state is 8
[   32.465308] CPU: 0 PID: 416 Comm: double_timer_ad Not tainted 5.2.0+ #65
[   32.465311] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-2.fc30 04/01/2014
[   32.465313] Call Trace:
[   32.465318]  dump_stack+0x7c/0xc0
[   32.465323]  __neigh_event_send+0x20c/0x880
[   32.465326]  ? ___neigh_create+0x846/0xfb0
[   32.465329]  ? neigh_lookup+0x2a9/0x410
[   32.465332]  ? neightbl_fill_info.constprop.0+0x800/0x800
[   32.465334]  neigh_add+0x4f8/0x5e0
[   32.465337]  ? neigh_xmit+0x620/0x620
[   32.465341]  ? find_held_lock+0x85/0xa0
[   32.465345]  rtnetlink_rcv_msg+0x204/0x570
[   32.465348]  ? rtnl_dellink+0x450/0x450
[   32.465351]  ? mark_held_locks+0x90/0x90
[   32.465354]  ? match_held_lock+0x1b/0x230
[   32.465357]  netlink_rcv_skb+0xc4/0x1d0
[   32.465360]  ? rtnl_dellink+0x450/0x450
[   32.465363]  ? netlink_ack+0x420/0x420
[   32.465366]  ? netlink_deliver_tap+0x115/0x560
[   32.465369]  ? __alloc_skb+0xc9/0x2f0
[   32.465372]  netlink_unicast+0x270/0x330
[   32.465375]  ? netlink_attachskb+0x2f0/0x2f0
[   32.465378]  netlink_sendmsg+0x34f/0x5a0
[   32.465381]  ? netlink_unicast+0x330/0x330
[   32.465385]  ? move_addr_to_kernel.part.0+0x20/0x20
[   32.465388]  ? netlink_unicast+0x330/0x330
[   32.465391]  sock_sendmsg+0x91/0xa0
[   32.465394]  ___sys_sendmsg+0x407/0x480
[   32.465397]  ? copy_msghdr_from_user+0x200/0x200
[   32.465401]  ? _raw_spin_unlock_irqrestore+0x37/0x40
[   32.465404]  ? lockdep_hardirqs_on+0x17d/0x250
[   32.465407]  ? __wake_up_common_lock+0xcb/0x110
[   32.465410]  ? __wake_up_common+0x230/0x230
[   32.465413]  ? netlink_bind+0x3e1/0x490
[   32.465416]  ? netlink_setsockopt+0x540/0x540
[   32.465420]  ? __fget_light+0x9c/0xf0
[   32.465423]  ? sockfd_lookup_light+0x8c/0xb0
[   32.465426]  __sys_sendmsg+0xa5/0x110
[   32.465429]  ? __ia32_sys_shutdown+0x30/0x30
[   32.465432]  ? __fd_install+0xe1/0x2c0
[   32.465435]  ? lockdep_hardirqs_off+0xb5/0x100
[   32.465438]  ? mark_held_locks+0x24/0x90
[   32.465441]  ? do_syscall_64+0xf/0x270
[   32.465444]  do_syscall_64+0x63/0x270
[   32.465448]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fix the issue unscheduling neigh_timer if selected entry is in 'IN_TIMER'
receiving a netlink request with NTF_USE flag set

Reported-by: Marek Majkowski <[email protected]>
Fixes: 0c5c2d3 ("neigh: Allow for user space users of the neighbour table")
Signed-off-by: Lorenzo Bianconi <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
popcornmix pushed a commit that referenced this issue Jul 31, 2019
[ Upstream commit 071c379 ]

Neigh timer can be scheduled multiple times from userspace adding
multiple neigh entries and forcing the neigh timer scheduling passing
NTF_USE in the netlink requests.
This will result in a refcount leak and in the following dump stack:

[   32.465295] NEIGH: BUG, double timer add, state is 8
[   32.465308] CPU: 0 PID: 416 Comm: double_timer_ad Not tainted 5.2.0+ #65
[   32.465311] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-2.fc30 04/01/2014
[   32.465313] Call Trace:
[   32.465318]  dump_stack+0x7c/0xc0
[   32.465323]  __neigh_event_send+0x20c/0x880
[   32.465326]  ? ___neigh_create+0x846/0xfb0
[   32.465329]  ? neigh_lookup+0x2a9/0x410
[   32.465332]  ? neightbl_fill_info.constprop.0+0x800/0x800
[   32.465334]  neigh_add+0x4f8/0x5e0
[   32.465337]  ? neigh_xmit+0x620/0x620
[   32.465341]  ? find_held_lock+0x85/0xa0
[   32.465345]  rtnetlink_rcv_msg+0x204/0x570
[   32.465348]  ? rtnl_dellink+0x450/0x450
[   32.465351]  ? mark_held_locks+0x90/0x90
[   32.465354]  ? match_held_lock+0x1b/0x230
[   32.465357]  netlink_rcv_skb+0xc4/0x1d0
[   32.465360]  ? rtnl_dellink+0x450/0x450
[   32.465363]  ? netlink_ack+0x420/0x420
[   32.465366]  ? netlink_deliver_tap+0x115/0x560
[   32.465369]  ? __alloc_skb+0xc9/0x2f0
[   32.465372]  netlink_unicast+0x270/0x330
[   32.465375]  ? netlink_attachskb+0x2f0/0x2f0
[   32.465378]  netlink_sendmsg+0x34f/0x5a0
[   32.465381]  ? netlink_unicast+0x330/0x330
[   32.465385]  ? move_addr_to_kernel.part.0+0x20/0x20
[   32.465388]  ? netlink_unicast+0x330/0x330
[   32.465391]  sock_sendmsg+0x91/0xa0
[   32.465394]  ___sys_sendmsg+0x407/0x480
[   32.465397]  ? copy_msghdr_from_user+0x200/0x200
[   32.465401]  ? _raw_spin_unlock_irqrestore+0x37/0x40
[   32.465404]  ? lockdep_hardirqs_on+0x17d/0x250
[   32.465407]  ? __wake_up_common_lock+0xcb/0x110
[   32.465410]  ? __wake_up_common+0x230/0x230
[   32.465413]  ? netlink_bind+0x3e1/0x490
[   32.465416]  ? netlink_setsockopt+0x540/0x540
[   32.465420]  ? __fget_light+0x9c/0xf0
[   32.465423]  ? sockfd_lookup_light+0x8c/0xb0
[   32.465426]  __sys_sendmsg+0xa5/0x110
[   32.465429]  ? __ia32_sys_shutdown+0x30/0x30
[   32.465432]  ? __fd_install+0xe1/0x2c0
[   32.465435]  ? lockdep_hardirqs_off+0xb5/0x100
[   32.465438]  ? mark_held_locks+0x24/0x90
[   32.465441]  ? do_syscall_64+0xf/0x270
[   32.465444]  do_syscall_64+0x63/0x270
[   32.465448]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fix the issue unscheduling neigh_timer if selected entry is in 'IN_TIMER'
receiving a netlink request with NTF_USE flag set

Reported-by: Marek Majkowski <[email protected]>
Fixes: 0c5c2d3 ("neigh: Allow for user space users of the neighbour table")
Signed-off-by: Lorenzo Bianconi <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
popcornmix pushed a commit that referenced this issue Jun 17, 2020
After previous fix for zero extension test_verifier tests #65 and #66 now
fail. Before the fix we can see the alu32 mov op at insn 10

10: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=invP(id=0,
              smin_value=4294967168,smax_value=4294967423,
              umin_value=4294967168,umax_value=4294967423,
              var_off=(0x0; 0x1ffffffff),
              s32_min_value=-2147483648,s32_max_value=2147483647,
              u32_min_value=0,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm
10: (bc) w1 = w1
11: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=invP(id=0,
              smin_value=0,smax_value=2147483647,
              umin_value=0,umax_value=4294967295,
              var_off=(0x0; 0xffffffff),
              s32_min_value=-2147483648,s32_max_value=2147483647,
              u32_min_value=0,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm

After the fix at insn 10 because we have 's32_min_value < 0' the following
step 11 now has 'smax_value=U32_MAX' where before we pulled the s32_max_value
bound into the smax_value as seen above in 11 with smax_value=2147483647.

10: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=inv(id=0,
             smin_value=4294967168,smax_value=4294967423,
             umin_value=4294967168,umax_value=4294967423,
             var_off=(0x0; 0x1ffffffff),
             s32_min_value=-2147483648, s32_max_value=2147483647,
             u32_min_value=0,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm
10: (bc) w1 = w1
11: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=inv(id=0,
             smin_value=0,smax_value=4294967295,
             umin_value=0,umax_value=4294967295,
             var_off=(0x0; 0xffffffff),
             s32_min_value=-2147483648, s32_max_value=2147483647,
             u32_min_value=0, u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm

The fall out of this is by the time we get to the failing instruction at
step 14 where previously we had the following:

14: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=inv(id=0,
             smin_value=72057594021150720,smax_value=72057594029539328,
             umin_value=72057594021150720,umax_value=72057594029539328,
             var_off=(0xffffffff000000; 0xffffff),
             s32_min_value=-16777216,s32_max_value=-1,
             u32_min_value=-16777216,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm
14: (0f) r0 += r1

We now have,

14: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=inv(id=0,
             smin_value=0,smax_value=72057594037927935,
             umin_value=0,umax_value=72057594037927935,
             var_off=(0x0; 0xffffffffffffff),
             s32_min_value=-2147483648,s32_max_value=2147483647,
             u32_min_value=0,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm
14: (0f) r0 += r1

In the original step 14 'smin_value=72057594021150720' this trips the logic
in the verifier function check_reg_sane_offset(),

 if (smin >= BPF_MAX_VAR_OFF || smin <= -BPF_MAX_VAR_OFF) {
	verbose(env, "value %lld makes %s pointer be out of bounds\n",
		smin, reg_type_str[type]);
	return false;
 }

Specifically, the 'smin <= -BPF_MAX_VAR_OFF' check. But with the fix
at step 14 we have bounds 'smin_value=0' so the above check is not tripped
because BPF_MAX_VAR_OFF=1<<29.

We have a smin_value=0 here because at step 10 the smaller smin_value=0 means
the subtractions at steps 11 and 12 bring the smin_value negative.

11: (17) r1 -= 2147483584
12: (17) r1 -= 2147483584
13: (77) r1 >>= 8

Then the shift clears the top bit and smin_value is set to 0. Note we still
have the smax_value in the fixed code so any reads will fail. An alternative
would be to have reg_sane_check() do both smin and smax value tests.

To fix the test we can omit the 'r1 >>=8' at line 13. This will change the
err string, but keeps the intention of the test as suggseted by the title,
"check after truncation of boundary-crossing range". If the verifier logic
changes a different value is likely to be thrown in the error or the error
will no longer be thrown forcing this test to be examined. With this change
we see the new state at step 13.

13: R0_w=map_value(id=0,off=0,ks=8,vs=8,imm=0)
    R1_w=invP(id=0,
              smin_value=-4294967168,smax_value=127,
              umin_value=0,umax_value=18446744073709551615,
              s32_min_value=-2147483648,s32_max_value=2147483647,
              u32_min_value=0,u32_max_value=-1)
    R10=fp0 fp-8_w=mmmmmmmm

Giving the expected out of bounds error, "value -4294967168 makes map_value
pointer be out of bounds" However, for unpriv case we see a different error
now because of the mixed signed bounds pointer arithmatic. This seems OK so
I've only added the unpriv_errstr for this. Another optino may have been to
do addition on r1 instead of subtraction but I favor the approach above
slightly.

Signed-off-by: John Fastabend <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/bpf/159077333942.6014.14004320043595756079.stgit@john-Precision-5820-Tower
popcornmix pushed a commit that referenced this issue Oct 24, 2022
When a console stack dump is initiated with CONFIG_GCOV_PROFILE_ALL
enabled, show_trace_log_lvl() gets out of sync with the ORC unwinder,
causing the stack trace to show all text addresses as unreliable:

  # echo l > /proc/sysrq-trigger
  [  477.521031] sysrq: Show backtrace of all active CPUs
  [  477.523813] NMI backtrace for cpu 0
  [  477.524492] CPU: 0 PID: 1021 Comm: bash Not tainted 6.0.0 #65
  [  477.525295] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014
  [  477.526439] Call Trace:
  [  477.526854]  <TASK>
  [  477.527216]  ? dump_stack_lvl+0xc7/0x114
  [  477.527801]  ? dump_stack+0x13/0x1f
  [  477.528331]  ? nmi_cpu_backtrace.cold+0xb5/0x10d
  [  477.528998]  ? lapic_can_unplug_cpu+0xa0/0xa0
  [  477.529641]  ? nmi_trigger_cpumask_backtrace+0x16a/0x1f0
  [  477.530393]  ? arch_trigger_cpumask_backtrace+0x1d/0x30
  [  477.531136]  ? sysrq_handle_showallcpus+0x1b/0x30
  [  477.531818]  ? __handle_sysrq.cold+0x4e/0x1ae
  [  477.532451]  ? write_sysrq_trigger+0x63/0x80
  [  477.533080]  ? proc_reg_write+0x92/0x110
  [  477.533663]  ? vfs_write+0x174/0x530
  [  477.534265]  ? handle_mm_fault+0x16f/0x500
  [  477.534940]  ? ksys_write+0x7b/0x170
  [  477.535543]  ? __x64_sys_write+0x1d/0x30
  [  477.536191]  ? do_syscall_64+0x6b/0x100
  [  477.536809]  ? entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [  477.537609]  </TASK>

This happens when the compiled code for show_stack() has a single word
on the stack, and doesn't use a tail call to show_stack_log_lvl().
(CONFIG_GCOV_PROFILE_ALL=y is the only known case of this.)  Then the
__unwind_start() skip logic hits an off-by-one bug and fails to unwind
all the way to the intended starting frame.

Fix it by reverting the following commit:

  f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")

The original justification for that commit no longer exists.  That
original issue was later fixed in a different way, with the following
commit:

  f2ac57a ("x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels")

Fixes: f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
Signed-off-by: Chen Zhongjin <[email protected]>
[jpoimboe: rewrite commit log]
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
popcornmix pushed a commit that referenced this issue Nov 6, 2022
[ Upstream commit 230db82 ]

When a console stack dump is initiated with CONFIG_GCOV_PROFILE_ALL
enabled, show_trace_log_lvl() gets out of sync with the ORC unwinder,
causing the stack trace to show all text addresses as unreliable:

  # echo l > /proc/sysrq-trigger
  [  477.521031] sysrq: Show backtrace of all active CPUs
  [  477.523813] NMI backtrace for cpu 0
  [  477.524492] CPU: 0 PID: 1021 Comm: bash Not tainted 6.0.0 #65
  [  477.525295] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014
  [  477.526439] Call Trace:
  [  477.526854]  <TASK>
  [  477.527216]  ? dump_stack_lvl+0xc7/0x114
  [  477.527801]  ? dump_stack+0x13/0x1f
  [  477.528331]  ? nmi_cpu_backtrace.cold+0xb5/0x10d
  [  477.528998]  ? lapic_can_unplug_cpu+0xa0/0xa0
  [  477.529641]  ? nmi_trigger_cpumask_backtrace+0x16a/0x1f0
  [  477.530393]  ? arch_trigger_cpumask_backtrace+0x1d/0x30
  [  477.531136]  ? sysrq_handle_showallcpus+0x1b/0x30
  [  477.531818]  ? __handle_sysrq.cold+0x4e/0x1ae
  [  477.532451]  ? write_sysrq_trigger+0x63/0x80
  [  477.533080]  ? proc_reg_write+0x92/0x110
  [  477.533663]  ? vfs_write+0x174/0x530
  [  477.534265]  ? handle_mm_fault+0x16f/0x500
  [  477.534940]  ? ksys_write+0x7b/0x170
  [  477.535543]  ? __x64_sys_write+0x1d/0x30
  [  477.536191]  ? do_syscall_64+0x6b/0x100
  [  477.536809]  ? entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [  477.537609]  </TASK>

This happens when the compiled code for show_stack() has a single word
on the stack, and doesn't use a tail call to show_stack_log_lvl().
(CONFIG_GCOV_PROFILE_ALL=y is the only known case of this.)  Then the
__unwind_start() skip logic hits an off-by-one bug and fails to unwind
all the way to the intended starting frame.

Fix it by reverting the following commit:

  f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")

The original justification for that commit no longer exists.  That
original issue was later fixed in a different way, with the following
commit:

  f2ac57a ("x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels")

Fixes: f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
Signed-off-by: Chen Zhongjin <[email protected]>
[jpoimboe: rewrite commit log]
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
popcornmix pushed a commit that referenced this issue Nov 11, 2022
[ Upstream commit 230db82 ]

When a console stack dump is initiated with CONFIG_GCOV_PROFILE_ALL
enabled, show_trace_log_lvl() gets out of sync with the ORC unwinder,
causing the stack trace to show all text addresses as unreliable:

  # echo l > /proc/sysrq-trigger
  [  477.521031] sysrq: Show backtrace of all active CPUs
  [  477.523813] NMI backtrace for cpu 0
  [  477.524492] CPU: 0 PID: 1021 Comm: bash Not tainted 6.0.0 #65
  [  477.525295] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014
  [  477.526439] Call Trace:
  [  477.526854]  <TASK>
  [  477.527216]  ? dump_stack_lvl+0xc7/0x114
  [  477.527801]  ? dump_stack+0x13/0x1f
  [  477.528331]  ? nmi_cpu_backtrace.cold+0xb5/0x10d
  [  477.528998]  ? lapic_can_unplug_cpu+0xa0/0xa0
  [  477.529641]  ? nmi_trigger_cpumask_backtrace+0x16a/0x1f0
  [  477.530393]  ? arch_trigger_cpumask_backtrace+0x1d/0x30
  [  477.531136]  ? sysrq_handle_showallcpus+0x1b/0x30
  [  477.531818]  ? __handle_sysrq.cold+0x4e/0x1ae
  [  477.532451]  ? write_sysrq_trigger+0x63/0x80
  [  477.533080]  ? proc_reg_write+0x92/0x110
  [  477.533663]  ? vfs_write+0x174/0x530
  [  477.534265]  ? handle_mm_fault+0x16f/0x500
  [  477.534940]  ? ksys_write+0x7b/0x170
  [  477.535543]  ? __x64_sys_write+0x1d/0x30
  [  477.536191]  ? do_syscall_64+0x6b/0x100
  [  477.536809]  ? entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [  477.537609]  </TASK>

This happens when the compiled code for show_stack() has a single word
on the stack, and doesn't use a tail call to show_stack_log_lvl().
(CONFIG_GCOV_PROFILE_ALL=y is the only known case of this.)  Then the
__unwind_start() skip logic hits an off-by-one bug and fails to unwind
all the way to the intended starting frame.

Fix it by reverting the following commit:

  f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")

The original justification for that commit no longer exists.  That
original issue was later fixed in a different way, with the following
commit:

  f2ac57a ("x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels")

Fixes: f1d9a2a ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
Signed-off-by: Chen Zhongjin <[email protected]>
[jpoimboe: rewrite commit log]
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
0lxb pushed a commit to 0lxb/rpi_linux that referenced this issue Jan 30, 2024
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