WARNING in blk_mq_free_tag_set

Status: upstream: reported syz repro on 2026/08/08 20:09
Subsystems: block
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+02b37e31e64ea5cb6d29@syzkaller.appspotmail.com
First crash: 15d, last: 2h05m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
3f7a095a assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in blk_mq_free_tag_set 2026/08/08 21:19 2026/08/08 21:19 2026/08/08 21:54 5d63f80b
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [block?] WARNING in blk_mq_free_tag_set 0 (1) 2026/08/08 20:09

Sample crash report:
------------[ cut here ]------------
timer_delete_sync(&sdp->delay_work) && rcu_segcblist_n_cbs(&sdp->srcu_cblist)
WARNING: kernel/rcu/srcutree.c:707 at cleanup_srcu_struct+0x3d6/0x8b0 kernel/rcu/srcutree.c:706, CPU#0: syz.1.758/6745
Modules linked in:
CPU: 0 UID: 0 PID: 6745 Comm: syz.1.758 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:cleanup_srcu_struct+0x3d6/0x8b0 kernel/rcu/srcutree.c:706
Code: c0 8b 00 48 83 7d 00 00 4c 8b 74 24 10 0f 85 dd 03 00 00 41 ff c5 41 83 e5 0f 41 83 fd 07 0f 86 e2 fe ff ff e9 ab 00 00 00 90 <0f> 0b 90 4c 8d b5 00 02 00 00 4c 89 f3 48 c1 eb 03 48 b8 00 00 00
RSP: 0018:ffffc9000348fcf0 EFLAGS: 00010206
RAX: 1ffffd1ffff816f5 RBX: 0000607edaf336c0 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: ffffffff8e4787e8 RDI: 00000000ffffffff
RBP: ffffe8ffffc0b6c0 R08: ffffffff907a477f R09: 1ffffffff20f48ef
R10: dffffc0000000000 R11: fffffbfff20f48f0 R12: ffff8880259b6800
R13: 0000000000000000 R14: ffffe8ffffc0b7a8 R15: 1ffffffff1ce93de
FS:  00005555845c8500(0000) GS:ffff888124cd8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555da99a48 CR3: 000000007f500000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 blk_mq_free_tag_set+0x617/0x790 block/blk-mq.c:4976
 loop_remove+0x4e/0xc0 drivers/block/loop.c:2143
 loop_control_remove drivers/block/loop.c:2201 [inline]
 loop_control_ioctl+0x4a6/0x5a0 drivers/block/loop.c:2243
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8008b9e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd6efdb308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8008e25fa0 RCX: 00007f8008b9e0d9
RDX: 0000000000000004 RSI: 0000000000004c81 RDI: 0000000000000003
RBP: 00007f8008c35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8008e25fac R14: 00007f8008e25fa0 R15: 00007f8008e25fa0
 </TASK>

Crashes (342):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/21 22:45 linux-next 903c1cf6dff9 1e72964b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/21 07:34 linux-next 7079a12d7506 1e72964b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/21 07:21 linux-next 7079a12d7506 1e72964b .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/20 04:20 linux-next 6a746cd265ae 1e72964b .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/18 21:39 linux-next e6664f2b33db 1e72964b .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in blk_mq_free_tag_set
2026/08/18 20:24 linux-next e6664f2b33db 1e72964b .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in blk_mq_free_tag_set
2026/08/18 19:16 linux-next e6664f2b33db 1e72964b .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in blk_mq_free_tag_set
2026/08/18 00:30 linux-next e6664f2b33db 1e72964b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/16 18:13 linux-next 4477a78374a5 746171ee .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/16 11:07 linux-next 4477a78374a5 746171ee .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/14 13:30 linux-next 2697ef8943c9 b13552fe .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/13 12:38 linux-next 28d012efb432 67796a05 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/10 01:48 linux-next 6b8c8af514d7 5d63f80b .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 19:54 linux-next 6b8c8af514d7 5d63f80b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 15:08 linux-next 6b8c8af514d7 5d63f80b .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 00:06 linux-next ea2bff00da89 e4ef95d6 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 21:16 linux-next ea2bff00da89 e4ef95d6 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 08:31 linux-next 1701fda2f58e c38879ea .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 07:00 linux-next 1701fda2f58e c38879ea .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/22 16:59 linux-next 903c1cf6dff9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/22 07:25 linux-next 903c1cf6dff9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/21 21:25 linux-next 903c1cf6dff9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in blk_mq_free_tag_set
2026/08/21 16:25 linux-next 903c1cf6dff9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in blk_mq_free_tag_set
2026/08/21 13:02 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/21 11:29 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/21 06:09 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/21 02:10 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/21 00:33 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/21 00:21 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/20 23:15 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/20 20:18 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/20 19:53 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/20 17:45 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/20 11:42 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/20 10:24 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/20 05:29 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/20 01:16 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/19 19:25 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in blk_mq_free_tag_set
2026/08/19 17:41 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/19 17:29 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/19 16:20 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/19 12:46 linux-next 5453bc3279e9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/19 11:14 linux-next 5453bc3279e9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/19 01:01 linux-next 5453bc3279e9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/19 01:00 linux-next 5453bc3279e9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/17 21:12 linux-next e6664f2b33db 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/17 17:48 linux-next 4477a78374a5 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/17 16:35 linux-next 4477a78374a5 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/17 04:30 linux-next 4477a78374a5 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/16 19:35 linux-next 4477a78374a5 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/16 15:39 linux-next 4477a78374a5 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/16 09:46 linux-next 4477a78374a5 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/15 10:45 linux-next 4477a78374a5 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/15 09:14 linux-next 4477a78374a5 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/15 06:43 linux-next 4477a78374a5 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/15 05:35 linux-next 2697ef8943c9 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/15 03:10 linux-next 2697ef8943c9 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/15 01:13 linux-next 2697ef8943c9 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/14 20:10 linux-next 2697ef8943c9 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/14 18:51 linux-next 2697ef8943c9 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/14 05:44 linux-next 2697ef8943c9 b13552fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/14 05:05 linux-next 2697ef8943c9 b13552fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
* Struck through repros no longer work on HEAD.