From 91e89c77322d2a65ede9f418642942f3c096a63b Mon Sep 17 00:00:00 2001
From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: Wed, 3 Nov 2021 18:02:35 +0100
Subject: [PATCH] cfg80211: fix possible NULL pointer dereference in cfg80211_stop_offchan_radar_detection
Git-commit: 91e89c77322d2a65ede9f418642942f3c096a63b
Patch-mainline: v5.17-rc1
References: bsc#1209980
Fix the following NULL pointer dereference in
cfg80211_stop_offchan_radar_detection routine that occurs when hostapd
is stopped during the CAC on offchannel chain:
Sat Jan 1 0[ 779.567851] ESR = 0x96000005
0:12:50 2000 dae[ 779.572346] EC = 0x25: DABT (current EL), IL = 32 bits
mon.debug hostap[ 779.578984] SET = 0, FnV = 0
D: hostapd_inter[ 779.583445] EA = 0, S1PTW = 0
face_deinit_free[ 779.587936] Data abort info:
: num_bss=1 conf[ 779.592224] ISV = 0, ISS = 0x00000005
->num_bss=1
Sat[ 779.597403] CM = 0, WnR = 0
Jan 1 00:12:50[ 779.601749] user pgtable: 4k pages, 39-bit VAs, pgdp=00000000418b2000
2000 daemon.deb[ 779.609601] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
ug hostapd: host[ 779.619657] Internal error: Oops: 96000005 [#1] SMP
[ 779.770810] CPU: 0 PID: 2202 Comm: hostapd Not tainted 5.10.75 #0
[ 779.776892] Hardware name: MediaTek MT7622 RFB1 board (DT)
[ 779.782370] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--)
[ 779.788384] pc : cfg80211_chandef_valid+0x10/0x490 [cfg80211]
[ 779.794128] lr : cfg80211_check_station_change+0x3190/0x3950 [cfg80211]
[ 779.800731] sp : ffffffc01204b7e0
[ 779.804036] x29: ffffffc01204b7e0 x28: ffffff80039bdc00
[ 779.809340] x27: 0000000000000000 x26: ffffffc008cb3050
[ 779.814644] x25: 0000000000000000 x24: 0000000000000002
[ 779.819948] x23: ffffff8002630000 x22: ffffff8003e748d0
[ 779.825252] x21: 0000000000000cc0 x20: ffffff8003da4a00
[ 779.830556] x19: 0000000000000000 x18: ffffff8001bf7ce0
[ 779.835860] x17: 00000000ffffffff x16: 0000000000000000
[ 779.841164] x15: 0000000040d59200 x14: 00000000000019c0
[ 779.846467] x13: 00000000000001c8 x12: 000636b9e9dab1c6
[ 779.851771] x11: 0000000000000141 x10: 0000000000000820
[ 779.857076] x9 : 0000000000000000 x8 : ffffff8003d7d038
[ 779.862380] x7 : 0000000000000000 x6 : ffffff8003d7d038
[ 779.867683] x5 : 0000000000000e90 x4 : 0000000000000038
[ 779.872987] x3 : 0000000000000002 x2 : 0000000000000004
[ 779.878291] x1 : 0000000000000000 x0 : 0000000000000000
[ 779.883594] Call trace:
[ 779.886039] cfg80211_chandef_valid+0x10/0x490 [cfg80211]
[ 779.891434] cfg80211_check_station_change+0x3190/0x3950 [cfg80211]
[ 779.897697] nl80211_radar_notify+0x138/0x19c [cfg80211]
[ 779.903005] cfg80211_stop_offchan_radar_detection+0x7c/0x8c [cfg80211]
[ 779.909616] __cfg80211_leave+0x2c/0x190 [cfg80211]
[ 779.914490] cfg80211_register_netdevice+0x1c0/0x6d0 [cfg80211]
[ 779.920404] raw_notifier_call_chain+0x50/0x70
[ 779.924841] call_netdevice_notifiers_info+0x54/0xa0
[ 779.929796] __dev_close_many+0x40/0x100
[ 779.933712] __dev_change_flags+0x98/0x190
[ 779.937800] dev_change_flags+0x20/0x60
[ 779.941628] devinet_ioctl+0x534/0x6d0
[ 779.945370] inet_ioctl+0x1bc/0x230
[ 779.948849] sock_do_ioctl+0x44/0x200
[ 779.952502] sock_ioctl+0x268/0x4c0
[ 779.955985] __arm64_sys_ioctl+0xac/0xd0
[ 779.959900] el0_svc_common.constprop.0+0x60/0x110
[ 779.964682] do_el0_svc+0x1c/0x24
[ 779.967990] el0_svc+0x10/0x1c
[ 779.971036] el0_sync_handler+0x9c/0x120
[ 779.974950] el0_sync+0x148/0x180
[ 779.978259] Code: a9bc7bfd 910003fd a90153f3 aa0003f3 (f9400000)
[ 779.984344] ---[ end trace 0e67b4f5d6cdeec7 ]---
[ 779.996400] Kernel panic - not syncing: Oops: Fatal exception
[ 780.002139] SMP: stopping secondary CPUs
[ 780.006057] Kernel Offset: disabled
[ 780.009537] CPU features: 0x0000002,04002004
[ 780.013796] Memory Limit: none
Fixes: b8f5facf286b ("cfg80211: implement APIs for dedicated radar detection HW")
Reported-by: Evelyn Tsai <evelyn.tsai@mediatek.com>
Tested-by: Evelyn Tsai <evelyn.tsai@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/c2e34c065bf8839c5ffa45498ae154021a72a520.1635958796.git.lorenzo@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
net/wireless/mlme.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 840795828d4f..ac2e5e732d94 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -982,6 +982,9 @@ __cfg80211_offchan_cac_event(struct cfg80211_registered_device *rdev,
lockdep_assert_wiphy(&rdev->wiphy);
+ if (!cfg80211_chandef_valid(chandef))
+ return;
+
if (event != NL80211_RADAR_CAC_STARTED && !rdev->offchan_radar_wdev)
return;
@@ -1096,6 +1099,6 @@ void cfg80211_stop_offchan_radar_detection(struct wireless_dev *wdev)
rdev_set_radar_offchan(rdev, NULL);
- __cfg80211_offchan_cac_event(rdev, NULL, NULL,
+ __cfg80211_offchan_cac_event(rdev, wdev, &rdev->offchan_radar_chandef,
NL80211_RADAR_CAC_ABORTED);
}
--
2.35.3