WARNING in blk_mq_dispatch_rq_list

Status: upstream: reported on 2026/08/22 00:10
Subsystems: block
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+49b69d460fb5134ee1d7@syzkaller.appspotmail.com
First crash: 14d, last: 2d12h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
cda555e1 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ✅ VMHostTrigger: ❌ WARNING in blk_mq_dispatch_rq_list 2026/08/19 00:00 2026/08/19 00:00 2026/08/19 01:06 1e72964b
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [block?] WARNING in blk_mq_dispatch_rq_list 0 (1) 2026/08/22 00:10

Sample crash report:
------------[ cut here ]------------
WARNING: block/blk-mq.c:2107 at blk_mq_dispatch_rq_list+0x960/0x13a8 block/blk-mq.c:2107, CPU#0: kworker/0:1H/4406
Modules linked in:
CPU: 0 UID: 0 PID: 4406 Comm: kworker/0:1H Tainted: G      D      L      syzkaller #0 PREEMPT 
Tainted: [D]=DIE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
Workqueue: kblockd blk_mq_run_work_fn
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : blk_mq_dispatch_rq_list+0x960/0x13a8 block/blk-mq.c:2107
lr : blk_mq_dispatch_rq_list+0x960/0x13a8 block/blk-mq.c:2107
sp : ffff800097ab77e0
x29: ffff800097ab78c0 x28: 0000000000000000 x27: 0000000000000000
x26: 1fffe00019096302 x25: ffff0000c84b1848 x24: ffff0000c80d8800
x23: dfff800000000000 x22: ffff0000c84b1810 x21: ffff800097ab7a48
x20: ffff800097ab7a40 x19: ffff0000c80d8948 x18: 00000000ffffffff
x17: ffff80008a7d6000 x16: 0000000000000004 x15: ffff80008a35fda0
x14: ffff80008a5d5e28 x13: 0000000000000002 x12: 0000000000000000
x11: 0000000000000000 x10: ffff700012f56f12 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffff80008ab40b28 x4 : 0000000000000000 x3 : 0000000000000010
x2 : 0000000000000000 x1 : ffff0000c82557c0 x0 : 0000000000000000
Call trace:
 blk_mq_dispatch_rq_list+0x960/0x13a8 block/blk-mq.c:2107 (P)
 __blk_mq_sched_dispatch_requests+0x250/0x10e8 block/blk-mq-sched.c:299
 blk_mq_sched_dispatch_requests+0xa8/0x158 block/blk-mq-sched.c:329
 blk_mq_run_work_fn+0x214/0x2e4 block/blk-mq.c:2532
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0x788/0x10b8 kernel/workqueue.c:3405
 worker_thread+0x798/0xbd0 kernel/workqueue.c:3486
 kthread+0x304/0x3d4 kernel/kthread.c:436
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:838
irq event stamp: 9394
hardirqs last  enabled at (9393): [<ffff800086932104>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:187 [inline]
hardirqs last  enabled at (9393): [<ffff800086932104>] _raw_spin_unlock_irq+0x30/0x80 kernel/locking/spinlock.c:206
hardirqs last disabled at (9394): [<ffff80008690cc28>] el1_brk64+0x20/0x54 arch/arm64/kernel/entry-common.c:445
softirqs last  enabled at (9218): [<ffff800084ca9280>] local_bh_enable include/linux/bottom_half.h:33 [inline]
softirqs last  enabled at (9218): [<ffff800084ca9280>] flush_backlog+0x878/0xc58 net/core/dev.c:6536
softirqs last disabled at (9214): [<ffff800084ca8aec>] __skb_queue_head_init include/linux/skbuff.h:2291 [inline]
softirqs last disabled at (9214): [<ffff800084ca8aec>] flush_backlog+0xe4/0xc58 net/core/dev.c:6513
---[ end trace 0000000000000000 ]---
 non-slab/vmalloc memory
list_del corruption. next->prev should be ffff0000c84b1848, but was ffff800097ab7a40. (next=ffff0000c84b1848)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:67!

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/29 08:15 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci f1b8fa82cab7 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in blk_mq_dispatch_rq_list
2026/08/28 14:31 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci f1b8fa82cab7 bcbc8ceb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in blk_mq_dispatch_rq_list
2026/08/26 15:52 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 68f892e99df9 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in blk_mq_dispatch_rq_list
2026/08/24 13:22 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 21d6ac051080 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in blk_mq_dispatch_rq_list
2026/08/20 19:30 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 21d6ac051080 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in blk_mq_dispatch_rq_list
2026/08/18 08:11 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 21d6ac051080 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in blk_mq_dispatch_rq_list
2026/08/17 19:24 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 21d6ac051080 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in blk_mq_dispatch_rq_list
* Struck through repros no longer work on HEAD.