WARNING in nsim_dev_netdevice_event

Status: upstream: reported on 2026/10/27 18:35
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+a104228f8a378b00e6ad@syzkaller.appspotmail.com
First crash: 4d03h, last: 2d02h
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
9963167f repro-c Reproduced: ✅ ❓ WARNING in nsim_dev_netdevice_event 2026/10/26 00:00 2026/10/26 00:00 2026/10/26 02:22 1d9ca40b
6e11f73d assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ FuzzingArtifact: ❌ MemoryCorruption: ✅ NetworkNeedsSetup: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ WARNING in nsim_dev_netdevice_event 2026/10/25 00:00 2026/10/25 00:00 2026/10/25 01:12 1d9ca40b
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [net?] WARNING in nsim_dev_netdevice_event 0 (1) 2026/10/27 18:35
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/10/26 10:15 1h27m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 12392d40a3be2d79bc168bdb9ae6d7227b1dd17e no crash job log log

Sample crash report:
: left promiscuous mode
P: left promiscuous mode
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline], CPU#1: kworker/u8:3/50
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x132a/0x15a0 kernel/locking/mutex.c:821, CPU#1: kworker/u8:3/50
Modules linked in:
CPU: 1 UID: 0 PID: 50 Comm: kworker/u8:3 Tainted: G             L       syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: netns cleanup_net
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:625 [inline]
RIP: 0010:__mutex_lock+0x1331/0x15a0 kernel/locking/mutex.c:821
Code: 23 9d 91 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 46 02 00 00 83 3d 43 35 9e 05 00 75 13 48 8d 3d a6 34 a1 05 48 c7 c6 e0 27 2d 8c <67> 48 0f b9 3a 90 e9 1d ee ff ff 90 0f 0b 90 e9 f0 f1 ff ff 90 0f
RSP: 0018:ffffc90000ba7040 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888021a8be80
RDX: 0000000000000000 RSI: ffffffff8c2d27e0 RDI: ffffffff91a02350
RBP: ffffc90000ba71c8 R08: ffffffff919d23e3 R09: 1ffffffff233a47c
R10: dffffc0000000000 R11: fffffbfff233a47d R12: ffff88807c371500
R13: 0000000000000000 R14: 1ffff92000174e1c R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88812373c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb6d95f62f8 CR3: 00000000361d6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 nsim_dev_hwstats_event_unregister drivers/net/netdevsim/hwstats.c:174 [inline]
 nsim_dev_hwstats_event drivers/net/netdevsim/hwstats.c:192 [inline]
 nsim_dev_netdevice_event+0x1e8/0x830 drivers/net/netdevsim/hwstats.c:207
 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:86
 call_netdevice_notifiers_info+0x8c/0x100 net/core/dev.c:2310
 call_netdevice_notifiers_extack net/core/dev.c:2351 [inline]
 call_netdevice_notifiers net/core/dev.c:2365 [inline]
 unregister_netdevice_many_notify+0x1432/0x1d80 net/core/dev.c:12697
 unregister_netdevice_many net/core/dev.c:12768 [inline]
 unregister_netdevice_queue+0x2f5/0x340 net/core/dev.c:12564
 unregister_netdevice include/linux/netdevice.h:3509 [inline]
 _cfg80211_unregister_wdev+0x1c4/0x8e0 net/wireless/core.c:1503
 ieee80211_remove_interfaces+0x49c/0x6a0 net/mac80211/iface.c:2528
 ieee80211_unregister_hw+0x5d/0x2d0 net/mac80211/main.c:1725
 mac80211_hwsim_del_radio+0x31a/0x500 drivers/net/wireless/virtual/mac80211_hwsim_main.c:6302
 hwsim_exit_net+0xe91/0xf50 drivers/net/wireless/virtual/mac80211_hwsim_main.c:7365
 ops_exit_list net/core/net_namespace.c:200 [inline]
 ops_undo_list+0x451/0x8f0 net/core/net_namespace.c:253
 cleanup_net+0x572/0x810 net/core/net_namespace.c:706
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 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:	23 9d 91 48 c1 e8    	and    -0x173eb76f(%rbp),%ebx
   6:	03 0f                	add    (%rdi),%ecx
   8:	b6 04                	mov    $0x4,%dh
   a:	18 84 c0 0f 85 46 02 	sbb    %al,0x246850f(%rax,%rax,8)
  11:	00 00                	add    %al,(%rax)
  13:	83 3d 43 35 9e 05 00 	cmpl   $0x0,0x59e3543(%rip)        # 0x59e355d
  1a:	75 13                	jne    0x2f
  1c:	48 8d 3d a6 34 a1 05 	lea    0x5a134a6(%rip),%rdi        # 0x5a134c9
  23:	48 c7 c6 e0 27 2d 8c 	mov    $0xffffffff8c2d27e0,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	90                   	nop
  30:	e9 1d ee ff ff       	jmp    0xffffee52
  35:	90                   	nop
  36:	0f 0b                	ud2
  38:	90                   	nop
  39:	e9 f0 f1 ff ff       	jmp    0xfffff22e
  3e:	90                   	nop
  3f:	0f                   	.byte 0xf

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/25 19:47 upstream 21a7f44fd076 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nsim_dev_netdevice_event
2026/10/25 19:47 upstream 21a7f44fd076 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in nsim_dev_netdevice_event
2026/10/23 18:33 upstream 734bef548a96 d566bfda .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in nsim_dev_netdevice_event
* Struck through repros no longer work on HEAD.