WARNING in v4l2_ctrl_cluster

Status: upstream: reported C repro on 2026/08/03 12:49
Subsystems: media
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+2d417475ba9d6d02cfc9@syzkaller.appspotmail.com
First crash: 39d, last: 7d02h
▶ ▼ ✨ AI Jobs (6)
ID Workflow Result Correct Bug Created Started Finished Revision
bd2c6ef0 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ✅ ❓ WARNING in v4l2_ctrl_cluster 2026/08/18 00:18 2026/08/18 00:18 2026/08/18 01:07 1e72964b
f45308e2 repro-c Reproduced: ✅ ❓ WARNING in v4l2_ctrl_cluster 2026/08/16 13:31 2026/08/16 13:31 2026/08/16 16:09 746171ee
8d590d51 assessment-security 💥 WARNING in v4l2_ctrl_cluster 2026/08/09 10:57 2026/08/09 10:57 2026/08/09 10:57 5d63f80b
f2aa231a assessment-security 💥 WARNING in v4l2_ctrl_cluster 2026/08/05 00:05 2026/08/05 00:05 2026/08/05 00:05 d4abbeac
15bfcdea assessment-security 💥 WARNING in v4l2_ctrl_cluster 2026/08/02 01:08 2026/08/02 01:08 2026/08/02 01:08 e611ffe1
643c15d8 assessment-security 💥 WARNING in v4l2_ctrl_cluster 2026/08/01 01:03 2026/08/01 01:03 2026/08/01 01:03 7664cf44
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [media?] WARNING in v4l2_ctrl_cluster 0 (2) 2026/08/17 11:24
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2026/08/31 12:31 18m retest repro upstream report job log log
2026/08/17 08:59 21m nogikh@google.com upstream report job log log

Sample crash report:
usb 5-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
hackrf 5-1:1.0: Board ID: 02
hackrf 5-1:1.0: Firmware version: 
------------[ cut here ]------------
ncontrols == 0 || controls[0] == NULL
WARNING: drivers/media/v4l2-core/v4l2-ctrls-core.c:2493 at v4l2_ctrl_cluster+0x1a1/0x230 drivers/media/v4l2-core/v4l2-ctrls-core.c:2493, CPU#0: kworker/0:1/10
Modules linked in:
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: usb_hub_wq hub_event
RIP: 0010:v4l2_ctrl_cluster+0x1a1/0x230 drivers/media/v4l2-core/v4l2-ctrls-core.c:2493
Code: 03 38 d0 7c 08 84 d2 0f 85 88 00 00 00 0f b6 43 35 41 83 e7 01 41 c1 e7 02 83 e0 fb 44 09 f8 88 43 35 eb 09 e8 e0 16 f2 f9 90 <0f> 0b 90 e8 d7 16 f2 f9 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc900000d6f20 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff88185b47
RDX: ffff88801eeba540 RSI: ffffffff88185cc0 RDI: ffff88801eeba540
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000002 R14: ffff88802bff1628 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880d5bde000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc2c57dd58 CR3: 000000002b63c000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 v4l2_ctrl_auto_cluster+0x4e/0x3a0 drivers/media/v4l2-core/v4l2-ctrls-core.c:2515
 hackrf_probe.cold+0x5f0/0x12ef drivers/media/usb/hackrf/hackrf.c:1430
 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3772
 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3772
 usb_new_device.part.0+0xcc2/0x1686 drivers/usb/core/hub.c:2703
 usb_new_device include/linux/workqueue.h:714 [inline]
 hub_port_connect drivers/usb/core/hub.c:5575 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
 port_event drivers/usb/core/hub.c:5879 [inline]
 hub_event.cold+0x1e3/0xe90 drivers/usb/core/hub.c:5961
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/17 11:23 upstream 8d3ae59288f1 abc81b93 .config console log report C ci-qemu-upstream WARNING in v4l2_ctrl_cluster
2026/07/30 12:39 upstream 11028ab62899 abc81b93 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in v4l2_ctrl_cluster
* Struck through repros no longer work on HEAD.