From: syzbot <syzbot+2e02ccadb3c5522a5c59@syzkaller.appspotmail.com>
To: axboe@kernel.dk, dlemoal@kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: [syzbot] [block?] possible deadlock in sd_revalidate_disk
Date: Tue, 22 Sep 2026 04:54:56 -0700 [thread overview]
Message-ID: <6ab26c90.c68e76dc.23da29.00ab.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 9d80aa4617b3 Add linux-next specific files for 20260903
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=175ba915580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b370c26fb58c72f0
dashboard link: https://syzkaller.appspot.com/bug?extid=2e02ccadb3c5522a5c59
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/84a12994f553/disk-9d80aa46.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2329deeb3b2b/vmlinux-9d80aa46.xz
kernel image: https://storage.googleapis.com/syzbot-assets/689910d8c695/bzImage-9d80aa46.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2e02ccadb3c5522a5c59@syzkaller.appspotmail.com
sd 1:0:0:0: [sdb] Test Unit Ready failed: Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
sd 1:0:0:0: [sdb] Read Capacity(10) failed: Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
sd 1:0:0:0: [sdb] Sense not available.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
kworker/u8:3/49 is trying to acquire lock:
ffffffff8f090420 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:316 [inline]
ffffffff8f090420 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4636 [inline]
ffffffff8f090420 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4974 [inline]
ffffffff8f090420 (fs_reclaim){+.+.}-{0:0}, at: __do_kmalloc_node mm/slub.c:5418 [inline]
ffffffff8f090420 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_noprof+0xbc/0x710 mm/slub.c:5444
but task is already holding lock:
ffff888012ece3b8 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:1101 [inline]
ffff888012ece3b8 (&q->limits_lock){+.+.}-{4:4}, at: sd_revalidate_disk+0xb88/0xb350 drivers/scsi/sd.c:3803
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&q->limits_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821
queue_limits_start_update include/linux/blkdev.h:1101 [inline]
disk_update_zone_resources block/blk-zoned.c:2067 [inline]
blk_revalidate_disk_zones+0xad9/0x12e0 block/blk-zoned.c:2375
nvme_mpath_revalidate_zones+0x106/0x1c0 drivers/nvme/host/multipath.c:301
nvme_update_ns_info+0x984/0x1200 drivers/nvme/host/core.c:2622
nvme_alloc_ns drivers/nvme/host/core.c:4284 [inline]
nvme_scan_ns+0x2563/0x3640 drivers/nvme/host/core.c:4471
async_run_entry_fn+0x9d/0x430 kernel/async.c:129
process_one_work kernel/workqueue.c:3399 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3482
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3563
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #1 (&q->q_usage_counter(io)#77){++++}-{0:0}:
blk_alloc_queue+0x544/0x690 block/blk-core.c:504
__blk_alloc_disk+0xe3/0x1d0 block/genhd.c:1527
nvme_mpath_alloc_disk+0x5c2/0x8b0 drivers/nvme/host/multipath.c:769
nvme_alloc_ns_head drivers/nvme/host/core.c:4043 [inline]
nvme_init_ns_head drivers/nvme/host/core.c:4144 [inline]
nvme_alloc_ns drivers/nvme/host/core.c:4258 [inline]
nvme_scan_ns+0x1e0f/0x3640 drivers/nvme/host/core.c:4471
async_run_entry_fn+0x9d/0x430 kernel/async.c:129
process_one_work kernel/workqueue.c:3399 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3482
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3563
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #0 (fs_reclaim){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3209 [inline]
check_prevs_add kernel/locking/lockdep.c:3328 [inline]
validate_chain kernel/locking/lockdep.c:3952 [inline]
__lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
__fs_reclaim_acquire mm/page_alloc.c:4357 [inline]
fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4371
might_alloc include/linux/sched/mm.h:316 [inline]
slab_pre_alloc_hook mm/slub.c:4636 [inline]
slab_alloc_node mm/slub.c:4974 [inline]
__do_kmalloc_node mm/slub.c:5418 [inline]
__kmalloc_noprof+0xbc/0x710 mm/slub.c:5444
_kmalloc_noprof include/linux/slab.h:995 [inline]
sd_read_block_zero drivers/scsi/sd.c:3749 [inline]
sd_revalidate_disk+0x177d/0xb350 drivers/scsi/sd.c:3817
sd_probe+0x9f3/0x1180 drivers/scsi/sd.c:4101
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x254/0xae0 drivers/base/dd.c:706
__driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
__device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
__device_attach_async_helper+0x1e7/0x2b0 drivers/base/dd.c:1055
async_run_entry_fn+0x9d/0x430 kernel/async.c:129
process_one_work kernel/workqueue.c:3399 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3482
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3563
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
other info that might help us debug this:
Chain exists of:
fs_reclaim --> &q->q_usage_counter(io)#77 --> &q->limits_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&q->limits_lock);
lock(&q->q_usage_counter(io)#77);
lock(&q->limits_lock);
lock(fs_reclaim);
*** DEADLOCK ***
locks held by kworker/u8:3/49: 4, last CPU#0:
#0: ffff88801bedc940 ((wq_completion)async){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801bedc940 ((wq_completion)async){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801bedc940 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline]
#0: ffff88801bedc940 ((wq_completion)async){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482
#1: ffffc90000ba7c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90000ba7c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90000ba7c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline]
#1: ffffc90000ba7c40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482
#2: ffff888075d823c0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff888075d823c0 (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0xa4/0x2b0 drivers/base/dd.c:1041
#3: ffff888012ece3b8 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:1101 [inline]
#3: ffff888012ece3b8 (&q->limits_lock){+.+.}-{4:4}, at: sd_revalidate_disk+0xb88/0xb350 drivers/scsi/sd.c:3803
stack backtrace:
CPU: 0 UID: 0 PID: 49 Comm: kworker/u8:3 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: async async_run_entry_fn
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087
check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219
check_prev_add kernel/locking/lockdep.c:3209 [inline]
check_prevs_add kernel/locking/lockdep.c:3328 [inline]
validate_chain kernel/locking/lockdep.c:3952 [inline]
__lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
__fs_reclaim_acquire mm/page_alloc.c:4357 [inline]
fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4371
might_alloc include/linux/sched/mm.h:316 [inline]
slab_pre_alloc_hook mm/slub.c:4636 [inline]
slab_alloc_node mm/slub.c:4974 [inline]
__do_kmalloc_node mm/slub.c:5418 [inline]
__kmalloc_noprof+0xbc/0x710 mm/slub.c:5444
_kmalloc_noprof include/linux/slab.h:995 [inline]
sd_read_block_zero drivers/scsi/sd.c:3749 [inline]
sd_revalidate_disk+0x177d/0xb350 drivers/scsi/sd.c:3817
sd_probe+0x9f3/0x1180 drivers/scsi/sd.c:4101
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x254/0xae0 drivers/base/dd.c:706
__driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
__device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
__device_attach_async_helper+0x1e7/0x2b0 drivers/base/dd.c:1055
async_run_entry_fn+0x9d/0x430 kernel/async.c:129
process_one_work kernel/workqueue.c:3399 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3482
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3563
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
sd 1:0:0:0: [sdb] 0 512-byte logical blocks: (0 B/0 B)
sd 1:0:0:0: [sdb] 0-byte physical blocks
sd 1:0:0:0: [sdb] Write Protect is off
sd 1:0:0:0: [sdb] Mode Sense: 00 00 00 00
sd 1:0:0:0: [sdb] Asking for cache data failed
sd 1:0:0:0: [sdb] Assuming drive cache: write through
sd 1:0:0:0: [sdb] Attached SCSI removable disk
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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reply other threads:[~2026-09-22 11:54 UTC|newest]
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