WARNING in vb2_start_streaming

Status: upstream: reported on 2026/08/05 02:05
Subsystems: media
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+930e6201080a31e9d0c8@syzkaller.appspotmail.com
First crash: 95d, last: 1h13m
▶ ▼ ✨ AI Jobs (7)
ID Workflow Result Correct Bug Created Started Finished Revision
934c94b3 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ WARNING in vb2_start_streaming 2026/10/07 01:18 2026/10/07 01:18 2026/10/07 02:28 f7710056
92f0b96b assessment-security 💥 WARNING in vb2_start_streaming 2026/09/07 00:46 2026/09/07 00:46 2026/09/07 00:46 4f7b22a0
86c5c704 assessment-security 💥 WARNING in vb2_start_streaming 2026/08/22 00:32 2026/08/22 00:32 2026/08/22 00:32 1e72964b
830eb572 assessment-security 💥 WARNING in vb2_start_streaming 2026/08/14 00:06 2026/08/14 00:06 2026/08/14 00:06 0165196a
9c6e41ce assessment-security 💥 WARNING in vb2_start_streaming 2026/08/09 09:11 2026/08/09 09:11 2026/08/09 09:11 5d63f80b
9a484b91 assessment-security 💥 WARNING in vb2_start_streaming 2026/08/04 00:39 2026/08/04 00:39 2026/08/04 00:39 cb1adeae
0b19b2e9 assessment-security 💥 WARNING in vb2_start_streaming 2026/08/03 00:22 2026/08/03 00:22 2026/08/03 00:22 e611ffe1
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [media?] WARNING in vb2_start_streaming 0 (1) 2026/08/05 02:05
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in vb2_start_streaming origin:lts-only -1 syz, C done 3 82d 91d 0/3 upstream: reported C repro on 2026/08/05 08:25

Sample crash report:
------------[ cut here ]------------
!list_empty(&q->done_list)
WARNING: drivers/media/common/videobuf2/videobuf2-core.c:1821 at vb2_start_streaming+0x247/0x570 drivers/media/common/videobuf2/videobuf2-core.c:1821, CPU#2: syz.3.3964/23279
Modules linked in:
CPU: 2 UID: 0 PID: 23279 Comm: syz.3.3964 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:vb2_start_streaming+0x247/0x570 drivers/media/common/videobuf2/videobuf2-core.c:1821
Code: 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 80 3c 02 00 0f 85 b5 02 00 00 48 8b 83 68 01 00 00 49 39 c4 74 0d e8 9a 35 e2 f9 90 <0f> 0b 90 eb 02 31 ed e8 8d 35 e2 f9 89 e8 48 83 c4 30 5b 5d 41 5c
RSP: 0000:ffffc90002e4fa50 EFLAGS: 00010283
RAX: 00000000000027ef RBX: ffff88806deda770 RCX: ffffc90007779000
RDX: 0000000000080000 RSI: ffffffff88277866 RDI: ffff8880282c2540
RBP: 00000000ffffffed R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88806deda8d8
R13: 0000000000000000 R14: ffff88806deda7d0 R15: ffff88806deda7a0
FS:  0000000000000000(0000) GS:ffff888096de1000(0063) knlGS:00000000f547db40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f6fff000 CR3: 00000000739b9000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 vb2_core_streamon+0x26a/0x3c0 drivers/media/common/videobuf2/videobuf2-core.c:2336
 __vb2_init_fileio+0xcb7/0x1000 drivers/media/common/videobuf2/videobuf2-core.c:2949
 __vb2_perform_fileio+0x9ba/0x1380 drivers/media/common/videobuf2/videobuf2-core.c:3025
 vb2_fop_read+0x211/0x520 drivers/media/common/videobuf2/videobuf2-v4l2.c:1215
 v4l2_read+0x229/0x2c0 drivers/media/v4l2-core/v4l2-dev.c:316
 vfs_read+0x1e4/0xb40 fs/read_write.c:572
 ksys_read+0x12a/0x250 fs/read_write.c:716
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf708efec
Code: Unable to access opcode bytes at 0xf708efc2.
RSP: 002b:00000000f547d50c EFLAGS: 00000292 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000080002c00
RDX: 0000000000002020 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/01 02:03 upstream a2cf4ef33184 e611ffe1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in vb2_start_streaming
2026/11/04 20:19 linux-next 8b7179210b22 5af5b6c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in vb2_start_streaming
* Struck through repros no longer work on HEAD.