From: syzbot <syzbot+b380cbb218c1ef0fe808@syzkaller.appspotmail.com>
To: axboe@kernel.dk, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: [syzbot] [block?] BUG: unable to handle kernel paging request in __blk_mq_alloc_driver_tag
Date: Sat, 29 Aug 2026 22:57:28 -0700 [thread overview]
Message-ID: <6a93c648.08e933ee.dbf97.00fc.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: f1b8fa82cab7 Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=10697d79580000
kernel config: https://syzkaller.appspot.com/x/.config?x=d1128bc53f2ef7f3
dashboard link: https://syzkaller.appspot.com/bug?extid=b380cbb218c1ef0fe808
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/932d85a2bda2/disk-f1b8fa82.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5b6b8fb76e8d/vmlinux-f1b8fa82.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c246b61ee396/Image-f1b8fa82.gz.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b380cbb218c1ef0fe808@syzkaller.appspotmail.com
nvme nvme0: Does your device have a faulty power saving mode enabled?
nvme nvme0: Try "nvme_core.default_ps_max_latency_us=0 pcie_aspm=off pcie_port_pm=off" and report a bug
Unable to handle kernel paging request at virtual address dfff800000000000
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
Mem abort info:
ESR = 0x0000000096000005
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x05: level 1 translation fault
Data abort info:
ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0
[dfff800000000000] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] SMP
Modules linked in:
CPU: 0 UID: 0 PID: 4404 Comm: kworker/0:1H Not tainted syzkaller #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : blk_mq_tag_is_reserved block/blk-mq.h:224 [inline]
pc : __blk_mq_alloc_driver_tag+0x118/0x554 block/blk-mq.c:1844
lr : blk_mq_tag_busy block/blk-mq.h:211 [inline]
lr : __blk_mq_alloc_driver_tag+0xbc/0x554 block/blk-mq.c:1842
sp : ffff800099507780
x26: 0000000000000000 x25: 1fffe000190d6c82 x24: dfff800000000000
x23: ffff0000c8044400 x22: 0000000000000004 x21: 00000000ffffffff
x20: ffff0000c86b6400 x19: ffff0000c86b6410 x18: 00000000ffffffff
x17: ffff80008a7d6000 x16: 0000000000000004 x15: ffff80008a35fda0
x14: ffff80008a5d5e28 x13: 0000000000000002 x12: 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffff80008aa7bd88 x4 : 0000000000000000 x3 : ffff8000817944e8
x2 : 0000000000000000 x1 : ffff0000c81a3a80 x0 : 0000000000000000
Call trace:
blk_mq_get_driver_tag block/blk-mq.h:374 [inline]
blk_mq_prep_dispatch_rq block/blk-mq.c:2029 [inline]
blk_mq_dispatch_rq_list+0x298/0x13a8 block/blk-mq.c:2108
__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
worker_thread+0x798/0xbd0 kernel/workqueue.c:3486
kthread+0x304/0x3d4 kernel/kthread.c:436
Code: 35001b08 910012d6 b94002b5 d343fec8 (38f86908)
---[ end trace 0000000000000000 ]---
SMP: stopping secondary CPUs
Kernel Offset: disabled
CPU features: 0x14000000,003c0008,27020a02,a84ff6a7
Memory Limit: none
Rebooting in 86400 seconds..
----------------
Code disassembly (best guess):
0: 35001b08 cbnz w8, 0x360
4: 910012d6 add x22, x22, #0x4
8: b94002b5 ldr w21, [x21]
c: d343fec8 lsr x8, x22, #3
* 10: 38f86908 ldrsb w8, [x8, x24] <-- trapping instruction
---
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reply other threads:[~2026-08-30 5:57 UTC|newest]
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