syzbot
WARNING in drv_unassign_vif_chanctx (4)
Status:
upstream: reported on 2026/08/13 00:09
Subsystems:
wireless
Labels:
prio:low
[Documentation on labels]
Reported-by: syzbot+63a84ea9c0f57d6133fa@syzkaller.appspotmail.com
First crash: 21d, last: 1d02h
Sample crash report:
------------[ cut here ]------------
wlan0: Failed check-sdata-in-driver check, flags: 0x0
WARNING: net/mac80211/driver-ops.c:366 at drv_unassign_vif_chanctx+0x1ef/0x820 net/mac80211/driver-ops.c:366, CPU#1: kworker/u8:10/5850
Modules linked in:
CPU: 1 UID: 0 PID: 5850 Comm: kworker/u8:10 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Workqueue: netns cleanup_net
RIP: 0010:drv_unassign_vif_chanctx+0x1f7/0x820 net/mac80211/driver-ops.c:366
Code: 00 00 e8 cc 40 d1 f6 48 8b 34 24 48 81 c6 20 01 00 00 48 89 34 24 e8 b8 40 d1 f6 48 8d 3d f1 71 1b 06 8b 54 24 0c 48 8b 34 24 <67> 48 0f b9 3a eb 07 4c 8d b3 68 0a 00 00 e8 96 40 d1 f6 4c 89 f2
RSP: 0018:ffffc900047b73d0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8880541acec0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8880541ac120 RDI: ffffffff91560870
RBP: ffff8880541f0f40 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 6b636f6c5f6b726f R12: ffff8880541aef88
R13: ffff888056304c00 R14: ffff8880541ad928 R15: ffff8880541aec70
FS: 0000000000000000(0000) GS:ffff888123c69000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6451b8d050 CR3: 000000005e5dd000 CR4: 00000000003526f0
Call Trace:
<TASK>
ieee80211_assign_link_chanctx+0x5ec/0xeb0 net/mac80211/chan.c:1201
__ieee80211_link_release_channel+0x2f8/0x5b0 net/mac80211/chan.c:2178
ieee80211_link_release_channel+0x128/0x200 net/mac80211/chan.c:2494
ieee80211_teardown_sdata+0xc4/0x250 net/mac80211/iface.c:916
unregister_netdevice_many_notify+0x1407/0x2150 net/core/dev.c:12537
unregister_netdevice_many net/core/dev.c:12589 [inline]
unregister_netdevice_queue net/core/dev.c:12390 [inline]
unregister_netdevice_queue+0x30b/0x3c0 net/core/dev.c:12376
unregister_netdevice include/linux/netdevice.h:3487 [inline]
_cfg80211_unregister_wdev+0x66e/0x830 net/wireless/core.c:1425
ieee80211_remove_interfaces+0x34e/0x6e0 net/mac80211/iface.c:2492
ieee80211_unregister_hw+0x55/0x360 net/mac80211/main.c:1717
mac80211_hwsim_del_radio drivers/net/wireless/virtual/mac80211_hwsim_main.c:6251 [inline]
hwsim_exit_net+0x891/0x1500 drivers/net/wireless/virtual/mac80211_hwsim_main.c:7260
ops_exit_list net/core/net_namespace.c:200 [inline]
ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:253
cleanup_net+0x499/0x920 net/core/net_namespace.c:706
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387
process_scheduled_works kernel/workqueue.c:3470 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: e8 cc 40 d1 f6 call 0xf6d140d3
7: 48 8b 34 24 mov (%rsp),%rsi
b: 48 81 c6 20 01 00 00 add $0x120,%rsi
12: 48 89 34 24 mov %rsi,(%rsp)
16: e8 b8 40 d1 f6 call 0xf6d140d3
1b: 48 8d 3d f1 71 1b 06 lea 0x61b71f1(%rip),%rdi # 0x61b7213
22: 8b 54 24 0c mov 0xc(%rsp),%edx
26: 48 8b 34 24 mov (%rsp),%rsi
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: eb 07 jmp 0x38
31: 4c 8d b3 68 0a 00 00 lea 0xa68(%rbx),%r14
38: e8 96 40 d1 f6 call 0xf6d140d3
3d: 4c 89 f2 mov %r14,%rdx
* Struck through repros no longer work on HEAD.