INFO: task udevd:5166 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:22896 pid:5166 tgid:5166 ppid:1 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1794/0x4c40 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x161/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x700/0x14b0 kernel/locking/mutex.c:760
bdev_open+0xd6/0xe70 block/bdev.c:945
blkdev_open+0x453/0x5f0 block/fops.c:694
do_dentry_open+0x94e/0x13f0 fs/open.c:965
vfs_open+0x37/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2edd/0x3830 fs/namei.c:4046
do_filp_open+0x1f6/0x400 fs/namei.c:4073
do_sys_openat2+0x11d/0x1b0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x134/0x160 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x86/0x2e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fd6a83cb407
RSP: 002b:00007ffc19c17950 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd6a833f880 RCX: 00007fd6a83cb407
RDX: 00000000000a0800 RSI: 0000562e1e2407d0 RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000562e0c4b6100 R14: 0000000000000000 R15: 00007ffc19c17be0
INFO: task udevd:5166 is blocked on a mutex likely owned by task udevd:6134.
task:udevd state:D stack:21992 pid:6134 tgid:6134 ppid:5166 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1794/0x4c40 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x161/0x360 kernel/sched/core.c:7058
io_schedule+0x7d/0xd0 kernel/sched/core.c:7903
folio_wait_bit_common+0x7aa/0xb70 mm/filemap.c:1317
folio_wait_bit_killable mm/filemap.c:1462 [inline]
folio_wait_locked_killable include/linux/pagemap.h:1215 [inline]
filemap_read_folio+0x1ff/0x370 mm/filemap.c:2419
do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
read_mapping_folio include/linux/pagemap.h:991 [inline]
read_part_sector+0xb2/0x2a0 block/partitions/core.c:722
adfspart_check_ICS+0xa0/0xa50 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x759/0x14a0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:748
bdev_open+0x314/0xe70 block/bdev.c:957
blkdev_open+0x453/0x5f0 block/fops.c:694
do_dentry_open+0x94e/0x13f0 fs/open.c:965
vfs_open+0x37/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2edd/0x3830 fs/namei.c:4046
do_filp_open+0x1f6/0x400 fs/namei.c:4073
do_sys_openat2+0x11d/0x1b0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x134/0x160 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x86/0x2e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fd6a83cb407
RSP: 002b:00007ffc19c17790 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd6a833f880 RCX: 00007fd6a83cb407
RDX: 00000000000a0800 RSI: 0000562e1e219570 RDI: ffffffffffffff9c
RBP: 0000562e1e218910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000562e1e220650
R13: 0000562e1e226190 R14: 0000000000000000 R15: 0000562e1e220650
INFO: task syz.0.90:6595 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.90 state:D stack:28008 pid:6595 tgid:6594 ppid:6280 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1794/0x4c40 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x161/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x700/0x14b0 kernel/locking/mutex.c:760
bdev_release+0x1a5/0x650 block/bdev.c:1128
blkdev_release+0x11/0x20 block/fops.c:702
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1cd/0x260 kernel/task_work.c:227
get_signal+0x11c1/0x1310 kernel/signal.c:2807
arch_do_signal_or_restart+0x96/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x71/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x213/0x2e0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fba7258eec9
RSP: 002b:00007fba734cc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007fba727e5fa0 RCX: 00007fba7258eec9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007fba72611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fba727e6038 R14: 00007fba727e5fa0 R15: 00007fffa5e29878
INFO: task syz.0.90:6595 is blocked on a mutex likely owned by task udevd:6134.
task:udevd state:D stack:21992 pid:6134 tgid:6134 ppid:5166 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1794/0x4c40 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x161/0x360 kernel/sched/core.c:7058
io_schedule+0x7d/0xd0 kernel/sched/core.c:7903
folio_wait_bit_common+0x7aa/0xb70 mm/filemap.c:1317
folio_wait_bit_killable mm/filemap.c:1462 [inline]
folio_wait_locked_killable include/linux/pagemap.h:1215 [inline]
filemap_read_folio+0x1ff/0x370 mm/filemap.c:2419
do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
read_mapping_folio include/linux/pagemap.h:991 [inline]
read_part_sector+0xb2/0x2a0 block/partitions/core.c:722
adfspart_check_ICS+0xa0/0xa50 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x759/0x14a0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:748
bdev_open+0x314/0xe70 block/bdev.c:957
blkdev_open+0x453/0x5f0 block/fops.c:694
do_dentry_open+0x94e/0x13f0 fs/open.c:965
vfs_open+0x37/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2edd/0x3830 fs/namei.c:4046
do_filp_open+0x1f6/0x400 fs/namei.c:4073
do_sys_openat2+0x11d/0x1b0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x134/0x160 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x86/0x2e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fd6a83cb407
RSP: 002b:00007ffc19c17790 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd6a833f880 RCX: 00007fd6a83cb407
RDX: 00000000000a0800 RSI: 0000562e1e219570 RDI: ffffffffffffff9c
RBP: 0000562e1e218910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000562e1e220650
R13: 0000562e1e226190 R14: 0000000000000000 R15: 0000562e1e220650
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8db39660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8db39660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8db39660 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2a/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:2/36:
2 locks held by kworker/u9:0/51:
#0: ffff88802497d148 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88802497d148 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_scheduled_works+0x9b0/0x1780 kernel/workqueue.c:3319
#1: ffffc90000bb7ba0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90000bb7ba0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9eb/0x1780 kernel/workqueue.c:3319
1 lock held by udevd/5166:
#0: ffff888142ff3358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xd6/0xe70 block/bdev.c:945
2 locks held by getty/5557:
#0: ffff8880333e50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43a/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/6134:
#0: ffff888142ff3358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xd6/0xe70 block/bdev.c:945
1 lock held by syz.0.90/6595:
#0: ffff888142ff3358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a5/0x650 block/bdev.c:1128
4 locks held by syz.1.251/6970:
#0: ffff888024979230 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_start_device+0x189/0xb10 drivers/block/nbd.c:1479
#1: ffff888142fba478 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:1067 [inline]
#1: ffff888142fba478 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x28e/0x6a0 drivers/block/nbd.c:354
#2: ffff888142fb9e18 (&q->q_usage_counter(io)#50){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
#2: ffff888142fb9e18 (&q->q_usage_counter(io)#50){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x59/0x3e0 block/blk-settings.c:551
#3: ffff888142fb9e50 (&q->q_usage_counter(queue)#34){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
#3: ffff888142fb9e50 (&q->q_usage_counter(queue)#34){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x59/0x3e0 block/blk-settings.c:551
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x185/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39a/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x176/0x2e0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0x15a7/0x15f0 kernel/hung_task.c:491
kthread+0x70a/0x890 kernel/kthread.c:463
ret_from_fork+0x431/0x7a0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6970 Comm: syz.1.251 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lock_is_held_type+0xef/0x190 kernel/locking/lockdep.c:-1
Code: 8d 4c 89 e6 e8 22 fe a9 f9 eb cb 31 ed eb 20 83 fd ff 74 16 89 e9 31 c0 41 f6 47 22 03 0f 95 c0 31 ed 39 c1 40 0f 94 c5 eb 05 01 00 00 00 48 c7 c7 ee 8f 4c 8d e8 50 14 00 00 b8 ff ff ff ff
RSP: 0018:ffffc9000a9e7198 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff88802cd11e00 RCX: 0000000000000001
RDX: ffff88802cd11e00 RSI: ffffffff9956bf78 RDI: ffff88802cd129e8
RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200153ce18 R12: 0000000000000006
R13: 0000000000000046 R14: ffffffff9956bf78 R15: ffff88802cd129e8
FS: 00007fd00b25e6c0(0000) GS:ffff88812669b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd00b25df98 CR3: 00000000798ac000 CR4: 00000000003526f0
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
__uart_port_using_nbcon include/linux/serial_core.h:640 [inline]
__uart_port_nbcon_acquire include/linux/serial_core.h:674 [inline]
uart_port_lock_irqsave include/linux/serial_core.h:718 [inline]
serial8250_console_write+0x1bf/0x1ba0 drivers/tty/serial/8250/8250_port.c:3355
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x721/0xc30 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc0/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b3/0x790 kernel/printk/printk.c:2450
dev_vprintk_emit+0x333/0x3f0 drivers/base/core.c:4914
dev_printk_emit+0xdc/0x120 drivers/base/core.c:4925
_dev_warn+0x106/0x160 drivers/base/core.c:4981
nbd_clear_sock drivers/block/nbd.c:1416 [inline]
nbd_config_put+0x342/0x790 drivers/block/nbd.c:1440
nbd_release+0xfa/0x130 drivers/block/nbd.c:1745
bdev_release+0x532/0x650 block/bdev.c:-1
blkdev_release+0x11/0x20 block/fops.c:702
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1cd/0x260 kernel/task_work.c:227
get_signal+0x11c1/0x1310 kernel/signal.c:2807
arch_do_signal_or_restart+0x96/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x71/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x213/0x2e0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fd00a38eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd00b25e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007fd00a5e6180 RCX: 00007fd00a38eec9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007fd00a411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd00a5e6218 R14: 00007fd00a5e6180 R15: 00007fff2f2691a8