[syzbot] [wireless?] WARNING in drv_unassign_vif_chanctx (4)

syzbot <[email protected]> Wed, 12 Aug 2026 17:09:35 -0700
Newsgroups	org.kernel.vger.linux-wireless,org.kernel.vger.linux-kernel,org.kernel.vger.netdev
Message-ID	<[email protected]>
Hello,

syzbot found the following issue on:

HEAD commit:    9a143525f62b Merge tag 'ata-7.2-rc7' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14adefb9580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=aaf0da806f995318
dashboard link: https://syzkaller.appspot.com/bug?extid=63a84ea9c0f57d6133fa
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/36e9efe36a27/disk-9a143525.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cf7e7297c673/vmlinux-9a143525.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3ddbff8e1c81/bzImage-9a143525.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

------------[ cut here ]------------
wlan0: Failed check-sdata-in-driver check, flags: 0x0
WARNING: net/mac80211/driver-ops.c:366 at drv_unassign_vif_chanctx+0x498/0x7d0 net/mac80211/driver-ops.c:366, CPU#1: kworker/u8:33/10061
Modules linked in:
CPU: 1 UID: 0 PID: 10061 Comm: kworker/u8:33 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: netns cleanup_net
RIP: 0010:drv_unassign_vif_chanctx+0x4e5/0x7d0 net/mac80211/driver-ops.c:366
Code: 8d 78 0a 00 00 48 8b 02 48 8d b0 20 01 00 00 48 85 c0 48 0f 44 f1 42 0f b6 44 3d 00 84 c0 0f 85 95 01 00 00 41 8b 16 48 89 df <67> 48 0f b9 3a e9 04 fd ff ff e8 6c 20 8d f6 90 0f 0b 90 e9 3d fe
RSP: 0018:ffffc9000d7ff090 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffff90695800 RCX: ffff888037171938
RDX: 0000000000000000 RSI: ffff888037170120 RDI: ffffffff90695800
RBP: 1ffff11006e2e325 R08: ffffffff90574637 R09: 1ffffffff20ae8c6
R10: dffffc0000000000 R11: fffffbfff20ae8c7 R12: ffff888037172c70
R13: ffff888037170ec0 R14: ffff888037171928 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125055000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557e0c475950 CR3: 0000000051358000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ieee80211_assign_link_chanctx+0x234/0xcd0 net/mac80211/chan.c:1199
 __ieee80211_link_release_channel+0x3c6/0x610 net/mac80211/chan.c:2176
 ieee80211_teardown_sdata+0xc1/0x240 net/mac80211/iface.c:916
 unregister_netdevice_many_notify+0x1acd/0x2140 net/core/dev.c:12467
 unregister_netdevice_many net/core/dev.c:12509 [inline]
 unregister_netdevice_queue+0x2f5/0x340 net/core/dev.c:12320
 unregister_netdevice include/linux/netdevice.h:3474 [inline]
 _cfg80211_unregister_wdev+0x156/0x5a0 net/wireless/core.c:1422
 ieee80211_remove_interfaces+0x49c/0x6a0 net/mac80211/iface.c:2492
 ieee80211_unregister_hw+0x5d/0x2c0 net/mac80211/main.c:1718
 mac80211_hwsim_del_radio+0x28a/0x4a0 drivers/net/wireless/virtual/mac80211_hwsim_main.c:6226
 hwsim_exit_net+0xe8e/0xf50 drivers/net/wireless/virtual/mac80211_hwsim_main.c:7207
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:252
 cleanup_net+0x572/0x810 net/core/net_namespace.c:702
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 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:	8d 78 0a             	lea    0xa(%rax),%edi
   3:	00 00                	add    %al,(%rax)
   5:	48 8b 02             	mov    (%rdx),%rax
   8:	48 8d b0 20 01 00 00 	lea    0x120(%rax),%rsi
   f:	48 85 c0             	test   %rax,%rax
  12:	48 0f 44 f1          	cmove  %rcx,%rsi
  16:	42 0f b6 44 3d 00    	movzbl 0x0(%rbp,%r15,1),%eax
  1c:	84 c0                	test   %al,%al
  1e:	0f 85 95 01 00 00    	jne    0x1b9
  24:	41 8b 16             	mov    (%r14),%edx
  27:	48 89 df             	mov    %rbx,%rdi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	e9 04 fd ff ff       	jmp    0xfffffd38
  34:	e8 6c 20 8d f6       	call   0xf68d20a5
  39:	90                   	nop
  3a:	0f 0b                	ud2
  3c:	90                   	nop
  3d:	e9                   	.byte 0xe9
  3e:	3d                   	.byte 0x3d
  3f:	fe                   	.byte 0xfe


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