[v6.1] INFO: task hung in rescan_store
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syzbot
Aug 10, 2026, 4:13:38 AM (7 days ago) Aug 10
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: e4f7d8be268e Linux 6.1.182
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=110a2149580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=1aac7bd59d624cef2706
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/156843a60452/disk-e4f7d8be.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/719d532a0151/vmlinux-e4f7d8be.xz
kernel image: https://storage.googleapis.com/syzbot-assets/12160bc2f9ec/bzImage-e4f7d8be.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1aac7b...@syzkaller.appspotmail.com
INFO: task syz.0.10:4395 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.10 state:D stack:27920 pid:4395 ppid:4272 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
rescan_store+0xb2/0x150 drivers/pci/pci-sysfs.c:463
kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x482/0x9a0 fs/read_write.c:584
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7feae919e0d9
RSP: 002b:00007feaea02e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007feae9426090 RCX: 00007feae919e0d9
RDX: 0000000000000001 RSI: 0000200000000e00 RDI: 0000000000000006
RBP: 00007feae9235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feae9426128 R14: 00007feae9426090 R15: 00007ffd86bb0618
</TASK>
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527
2 locks held by getty/4029:
#0: ffff8880300cb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198
8 locks held by syz.0.10/4394:
#0: ffff88807c00a868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff8880192ea460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff8880781bb088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343
#3: ffffffff8d1f1488 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_stop_and_remove_bus_device_locked+0xe/0x30 drivers/pci/remove.c:123
#4: ffff8881432bc1b8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff8881432bc1b8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#4: ffff8881432bc1b8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#5: ffff88801ab35170 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#5: ffff88801ab35170 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#5: ffff88801ab35170 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#6: ffff888025aa80e0 (&shost->scan_mutex){+.+.}-{3:3}, at: scsi_remove_host+0x2e/0x730 drivers/scsi/hosts.c:169
#7: ffff888025c00370 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#7: ffff888025c00370 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#7: ffff888025c00370 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
5 locks held by syz.0.10/4395:
#0: ffff88807d24a368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff8880192ea460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff88802a749c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343
#3: ffff8881401f03a8 (kn->active#60){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#3: ffff8881401f03a8 (kn->active#60){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x520 fs/kernfs/file.c:344
#4: ffffffff8d1f1488 (pci_rescan_remove_lock){+.+.}-{3:3}, at: rescan_store+0xb2/0x150 drivers/pci/pci-sysfs.c:463
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf0e/0xf50 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 22 Comm: kworker/1:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
RIP: 0010:lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
RIP: 0010:lock_acquire+0x175/0x4a0 kernel/locking/lockdep.c:5675
Code: 00 43 c6 44 3d 08 00 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 4c 8b b4 24 a0 00 00 00 43 c6 44 3d 08 f8 fa <48> c7 c7 80 24 8c 8a e8 ef 33 cc 08 65 ff 05 a8 7f 9e 7e 45 31 c9
RSP: 0018:ffffc900001c7aa0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: edd8e68acf356c00
RDX: 0000000000000000 RSI: ffffffff8adf5dc0 RDI: ffffffff8adf5d80
RBP: ffffc900001c7bc0 R08: ffffffff8e210aef R09: 1ffffffff1c4215d
R10: dffffc0000000000 R11: fffffbfff1c4215e R12: 0000000000000001
R13: 1ffff92000038f60 R14: 0000000000000246 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056201246c660 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
wg_ratelimiter_gc_entries+0x59/0x450 drivers/net/wireguard/ratelimiter.c:63
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: e4f7d8be268e Linux 6.1.182
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=110a2149580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=1aac7bd59d624cef2706
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/156843a60452/disk-e4f7d8be.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/719d532a0151/vmlinux-e4f7d8be.xz
kernel image: https://storage.googleapis.com/syzbot-assets/12160bc2f9ec/bzImage-e4f7d8be.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1aac7b...@syzkaller.appspotmail.com
INFO: task syz.0.10:4395 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.10 state:D stack:27920 pid:4395 ppid:4272 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
rescan_store+0xb2/0x150 drivers/pci/pci-sysfs.c:463
kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x482/0x9a0 fs/read_write.c:584
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7feae919e0d9
RSP: 002b:00007feaea02e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007feae9426090 RCX: 00007feae919e0d9
RDX: 0000000000000001 RSI: 0000200000000e00 RDI: 0000000000000006
RBP: 00007feae9235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feae9426128 R14: 00007feae9426090 R15: 00007ffd86bb0618
</TASK>
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527
2 locks held by getty/4029:
#0: ffff8880300cb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198
8 locks held by syz.0.10/4394:
#0: ffff88807c00a868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff8880192ea460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff8880781bb088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343
#3: ffffffff8d1f1488 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_stop_and_remove_bus_device_locked+0xe/0x30 drivers/pci/remove.c:123
#4: ffff8881432bc1b8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff8881432bc1b8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#4: ffff8881432bc1b8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#5: ffff88801ab35170 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#5: ffff88801ab35170 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#5: ffff88801ab35170 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#6: ffff888025aa80e0 (&shost->scan_mutex){+.+.}-{3:3}, at: scsi_remove_host+0x2e/0x730 drivers/scsi/hosts.c:169
#7: ffff888025c00370 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#7: ffff888025c00370 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#7: ffff888025c00370 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
5 locks held by syz.0.10/4395:
#0: ffff88807d24a368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff8880192ea460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff88802a749c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343
#3: ffff8881401f03a8 (kn->active#60){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#3: ffff8881401f03a8 (kn->active#60){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x520 fs/kernfs/file.c:344
#4: ffffffff8d1f1488 (pci_rescan_remove_lock){+.+.}-{3:3}, at: rescan_store+0xb2/0x150 drivers/pci/pci-sysfs.c:463
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf0e/0xf50 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 22 Comm: kworker/1:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
RIP: 0010:lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
RIP: 0010:lock_acquire+0x175/0x4a0 kernel/locking/lockdep.c:5675
Code: 00 43 c6 44 3d 08 00 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 4c 8b b4 24 a0 00 00 00 43 c6 44 3d 08 f8 fa <48> c7 c7 80 24 8c 8a e8 ef 33 cc 08 65 ff 05 a8 7f 9e 7e 45 31 c9
RSP: 0018:ffffc900001c7aa0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: edd8e68acf356c00
RDX: 0000000000000000 RSI: ffffffff8adf5dc0 RDI: ffffffff8adf5d80
RBP: ffffc900001c7bc0 R08: ffffffff8e210aef R09: 1ffffffff1c4215d
R10: dffffc0000000000 R11: fffffbfff1c4215e R12: 0000000000000001
R13: 1ffff92000038f60 R14: 0000000000000246 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056201246c660 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
wg_ratelimiter_gc_entries+0x59/0x450 drivers/net/wireguard/ratelimiter.c:63
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
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