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: 4d02h, last: 9m
✨ 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)
WARNING: kernel/rcu/srcutree.c:706 at cleanup_srcu_struct+0x3aa/0x890 kernel/rcu/srcutree.c:706, CPU#1: syz.3.147/6410
Modules linked in:
CPU: 1 UID: 0 PID: 6410 Comm: syz.3.147 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+0x3aa/0x890 kernel/rcu/srcutree.c:706
Code: b9 8a 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 0e ff 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:ffffc9000474fcf0 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000607edacfc140 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e253559 RDI: 00000000ffffffff
RBP: ffffe8ffffc08140 R08: ffffffff9058fb7f R09: 1ffffffff20b1f6f
R10: dffffc0000000000 R11: fffffbfff20b1f70 R12: ffff88805e6de000
R13: 0000000000000000 R14: ffffffff8e5237d0 R15: 1ffffffff1ca47de
FS:  000055556c409500(0000) GS:ffff88812500c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f55e11ef9b8 CR3: 000000001f2b2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 blk_mq_free_tag_set+0x617/0x780 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+0x166/0x510 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce5259e0d9
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:00007fff707e6f18 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fce52825fa0 RCX: 00007fce5259e0d9
RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003
RBP: 00007fce52635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fce52825fac R14: 00007fce52825fa0 R15: 00007fce52825fa0
 </TASK>

Crashes (124):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2026/08/10 23:18 linux-next 3d08ff75a47a 039457bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/10 19:23 linux-next 6b8c8af514d7 039457bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/10 17:49 linux-next 6b8c8af514d7 039457bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/10 14:53 linux-next 6b8c8af514d7 039457bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/10 12:20 linux-next 6b8c8af514d7 558388e4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/10 11:03 linux-next 6b8c8af514d7 558388e4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/10 07:07 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/10 05:55 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/10 04:55 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/10 03:09 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/09 23:45 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/09 19:16 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/09 16:38 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/09 14:53 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/09 12:15 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/09 09:45 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/09 00:35 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 23:35 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 21:02 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 17:52 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 17:36 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 13:26 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 12:19 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 11:19 linux-next 6b8c8af514d7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 10:03 linux-next 6b8c8af514d7 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 02:48 linux-next 6b8c8af514d7 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 00:23 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 00:20 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 00:20 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 00:18 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 00:16 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 00:15 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/08 00:15 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 22:22 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 22:22 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 22:05 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 20:54 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 20:53 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 20:51 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 19:45 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 19:18 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 19:05 linux-next ea2bff00da89 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in blk_mq_free_tag_set
2026/08/07 18:48 linux-next ea2bff00da89 e4ef95d6 .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.