wifi: brcmfmac: fix invalid address access when enabling SCAN log level

BugLink: https://bugs.launchpad.net/bugs/1994179

[ Upstream commit aa666b6 ]

The variable i is changed when setting random MAC address and causes
invalid address access when printing the value of pi->reqs[i]->reqid.

We replace reqs index with ri to fix the issue.

[  136.726473] Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000000
[  136.737365] Mem abort info:
[  136.740172]   ESR = 0x96000004
[  136.743359]   Exception class = DABT (current EL), IL = 32 bits
[  136.749294]   SET = 0, FnV = 0
[  136.752481]   EA = 0, S1PTW = 0
[  136.755635] Data abort info:
[  136.758514]   ISV = 0, ISS = 0x00000004
[  136.762487]   CM = 0, WnR = 0
[  136.765522] user pgtable: 4k pages, 48-bit VAs, pgdp = 000000005c4e2577
[  136.772265] [0000000000000000] pgd=0000000000000000
[  136.777160] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[  136.782732] Modules linked in: brcmfmac(O) brcmutil(O) cfg80211(O) compat(O)
[  136.789788] Process wificond (pid: 3175, stack limit = 0x00000000053048fb)
[  136.796664] CPU: 3 PID: 3175 Comm: wificond Tainted: G           O      4.19.42-00001-g531a5f5 #1
[  136.805532] Hardware name: Freescale i.MX8MQ EVK (DT)
[  136.810584] pstate: 60400005 (nZCv daif +PAN -UAO)
[  136.815429] pc : brcmf_pno_config_sched_scans+0x6cc/0xa80 [brcmfmac]
[  136.821811] lr : brcmf_pno_config_sched_scans+0x67c/0xa80 [brcmfmac]
[  136.828162] sp : ffff00000e9a3880
[  136.831475] x29: ffff00000e9a3890 x28: ffff800020543400
[  136.836786] x27: ffff8000b1008880 x26: ffff0000012bf6a0
[  136.842098] x25: ffff80002054345c x24: ffff800088d22400
[  136.847409] x23: ffff0000012bf638 x22: ffff0000012bf6d8
[  136.852721] x21: ffff8000aced8fc0 x20: ffff8000ac164400
[  136.858032] x19: ffff00000e9a3946 x18: 0000000000000000
[  136.863343] x17: 0000000000000000 x16: 0000000000000000
[  136.868655] x15: ffff0000093f3b37 x14: 0000000000000050
[  136.873966] x13: 0000000000003135 x12: 0000000000000000
[  136.879277] x11: 0000000000000000 x10: ffff000009a61888
[  136.884589] x9 : 000000000000000f x8 : 0000000000000008
[  136.889900] x7 : 303a32303d726464 x6 : ffff00000a1f957d
[  136.895211] x5 : 0000000000000000 x4 : ffff00000e9a3942
[  136.900523] x3 : 0000000000000000 x2 : ffff0000012cead8
[  136.905834] x1 : ffff0000012bf6d8 x0 : 0000000000000000
[  136.911146] Call trace:
[  136.913623]  brcmf_pno_config_sched_scans+0x6cc/0xa80 [brcmfmac]
[  136.919658]  brcmf_pno_start_sched_scan+0xa4/0x118 [brcmfmac]
[  136.925430]  brcmf_cfg80211_sched_scan_start+0x80/0xe0 [brcmfmac]
[  136.931636]  nl80211_start_sched_scan+0x140/0x308 [cfg80211]
[  136.937298]  genl_rcv_msg+0x358/0x3f4
[  136.940960]  netlink_rcv_skb+0xb4/0x118
[  136.944795]  genl_rcv+0x34/0x48
[  136.947935]  netlink_unicast+0x264/0x300
[  136.951856]  netlink_sendmsg+0x2e4/0x33c
[  136.955781]  __sys_sendto+0x120/0x19c

Signed-off-by: Wright Feng <[email protected]>
Signed-off-by: Chi-hsien Lin <[email protected]>
Signed-off-by: Ahmad Fatoum <[email protected]>
Signed-off-by: Alvin Šipraga <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c

@@ -158,12 +158,12 @@ static int brcmf_pno_set_random(struct brcmf_if *ifp, struct brcmf_pno_info *pi)
 	struct brcmf_pno_macaddr_le pfn_mac;
 	u8 *mac_addr = NULL;
 	u8 *mac_mask = NULL;
-	int err, i;
+	int err, i, ri;
 
-	for (i = 0; i < pi->n_reqs; i++)
-		if (pi->reqs[i]->flags & NL80211_SCAN_FLAG_RANDOM_ADDR) {
-			mac_addr = pi->reqs[i]->mac_addr;
-			mac_mask = pi->reqs[i]->mac_addr_mask;
+	for (ri = 0; ri < pi->n_reqs; ri++)
+		if (pi->reqs[ri]->flags & NL80211_SCAN_FLAG_RANDOM_ADDR) {
+			mac_addr = pi->reqs[ri]->mac_addr;
+			mac_mask = pi->reqs[ri]->mac_addr_mask;
 			break;
 		}
 
@@ -185,7 +185,7 @@ static int brcmf_pno_set_random(struct brcmf_if *ifp, struct brcmf_pno_info *pi)
 	pfn_mac.mac[0] |= 0x02;
 
 	brcmf_dbg(SCAN, "enabling random mac: reqid=%llu mac=%pM\n",
-		  pi->reqs[i]->reqid, pfn_mac.mac);
+		  pi->reqs[ri]->reqid, pfn_mac.mac);
 	err = brcmf_fil_iovar_data_set(ifp, "pfn_macaddr", &pfn_mac,
 				       sizeof(pfn_mac));
 	if (err)