syzbot


WARNING in ublk_uring_cmd_cancel_fn

Status: premoderation: reported C repro on 2026/04/24 10:43
Bug presence: origin:lts
[Documentation on labels]
Reported-by: syzbot+fd921c948c489fa263c7@syzkaller.appspotmail.com
First crash: 4d02h, last: 2d22h
Bug presence (2)
Date Name Commit Repro Result
2026/04/25 lts (merge base) e0b14bf06393 C [report] WARNING in ublk_uring_cmd_cancel_fn
2026/04/25 upstream (ToT) 897d54018cc9 C Didn't crash

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 377 at drivers/block/ublk_drv.c:1579 ublk_uring_cmd_cancel_fn+0x34f/0x410 drivers/block/ublk_drv.c:1579
Modules linked in:
CPU: 1 UID: 0 PID: 377 Comm: kworker/u8:5 Not tainted syzkaller #0 8cfc209e52ea19d19d7bf60324c052393309520c
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: iou_exit io_ring_exit_work
RIP: 0010:ublk_uring_cmd_cancel_fn+0x34f/0x410 drivers/block/ublk_drv.c:1579
Code: 5d e9 95 c1 4e 02 cc e8 2f 8e 32 fe 0f 0b eb e3 e8 26 8e 32 fe 0f 0b eb da e8 1d 8e 32 fe 0f 0b e9 4d fe ff ff e8 11 8e 32 fe <0f> 0b eb c5 44 89 e1 80 e1 07 fe c1 38 c1 0f 8c 0c fd ff ff 4c 89
RSP: 0018:ffffc9000108f990 EFLAGS: 00010293
RAX: ffffffff8355212f RBX: 1ffff11022a2ebbd RCX: ffff888116123900
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: ffffc9000108f9e0 R08: 0000000000000003 R09: 0000000000000004
R10: 0000000000000000 R11: ffffffff83551110 R12: ffff88811b9edf00
R13: ffff888115175dc0 R14: ffff888116137300 R15: ffff888116137310
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7c54f48060 CR3: 0000000116128000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 ublk_ch_uring_cmd+0x6f/0xa0 drivers/block/ublk_drv.c:1975
 io_uring_try_cancel_uring_cmd+0x1a1/0x280 io_uring/uring_cmd.c:68
 io_uring_try_cancel_requests+0x4ce/0x5a5 io_uring/io_uring.c:3192
 io_ring_exit_work+0x23c/0x83b io_uring/io_uring.c:2978
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d1/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
 kthread+0x2c6/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
---[ end trace 0000000000000000 ]---

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/24 10:42 android16-6.12 20bf5f5313ad 9cfb3ca7 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in ublk_uring_cmd_cancel_fn
2026/04/25 14:52 android16-6.12 1c5ded243bc2 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in ublk_uring_cmd_cancel_fn
2026/04/25 03:59 android16-6.12 1c5ded243bc2 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in ublk_uring_cmd_cancel_fn
2026/04/24 19:57 android16-6.12 3c3180064cc9 1c2b9291 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in ublk_uring_cmd_cancel_fn
2026/04/24 19:55 android16-6.12 3c3180064cc9 1c2b9291 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust WARNING in ublk_uring_cmd_cancel_fn
* Struck through repros no longer work on HEAD.