WARNING in vb2_video_unregister_device

Status: upstream: reported on 2026/08/22 00:21
Subsystems: media
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+f26bc23e42eeb548dee1@syzkaller.appspotmail.com
First crash: 8d19h, last: 8d19h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
39fb9c0c assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in vb2_video_unregister_device 2026/08/19 03:52 2026/08/19 03:52 2026/08/19 04:36 1e72964b
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [media?] WARNING in vb2_video_unregister_device 0 (1) 2026/08/22 00:21

Sample crash report:
usb 3-1: Decoder not found
em28xx 3-1:1.0: failed to create media graph
em28xx 3-1:1.0: V4L2 device radio0 deregistered
------------[ cut here ]------------
!vdev->queue
WARNING: drivers/media/common/videobuf2/videobuf2-v4l2.c:1264 at vb2_video_unregister_device+0x1f8/0x200 drivers/media/common/videobuf2/videobuf2-v4l2.c:1264, CPU#1: kworker/1:1/44
Modules linked in:
CPU: 1 UID: 0 PID: 44 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events request_module_async
RIP: 0010:vb2_video_unregister_device+0x1f8/0x200 drivers/media/common/videobuf2/videobuf2-v4l2.c:1264
Code: c6 28 4c 89 f0 48 c1 e8 03 80 3c 28 00 4c 8b 24 24 74 08 4c 89 f7 e8 97 0b 09 fa 49 c7 06 00 00 00 00 eb a6 e8 49 90 9a f9 90 <0f> 0b 90 e9 ae fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000b47990 EFLAGS: 00010293
RAX: ffffffff882d4ce7 RBX: 1ffff1100581b29b RCX: ffff888020ec9f40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffff88802c0d953f R09: 1ffff1100581b2a7
R10: dffffc0000000000 R11: ffffed100581b2a8 R12: ffff88802bb40c00
R13: ffff88802c0d8000 R14: ffff88802c0d94d8 R15: ffff88802c0d8f38
FS:  0000000000000000(0000) GS:ffff8881249ab000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9b1ded3000 CR3: 000000000ed48000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 em28xx_v4l2_init+0x1c39/0x3150 drivers/media/usb/em28xx/em28xx-video.c:3085
 em28xx_init_extension+0x120/0x1d0 drivers/media/usb/em28xx/em28xx-core.c:1248
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
 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>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/17 22:25 linux-next 4477a78374a5 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in vb2_video_unregister_device
* Struck through repros no longer work on HEAD.