INFO: task udevd:4180 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:24752 pid: 4180 ppid: 3561 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
wait_on_page_bit_common+0x8bf/0xeb0 mm/filemap.c:1356
wait_on_page_bit mm/filemap.c:1417 [inline]
wait_on_page_locked include/linux/pagemap.h:688 [inline]
wait_on_page_read mm/filemap.c:3437 [inline]
do_read_cache_page+0xae6/0x1010 mm/filemap.c:3480
read_mapping_page include/linux/pagemap.h:515 [inline]
read_part_sector+0xd7/0x4c0 block/partitions/core.c:726
adfspart_check_ICS+0xc3/0xe90 block/partitions/acorn.c:360
check_partition block/partitions/core.c:148 [inline]
blk_add_partitions block/partitions/core.c:611 [inline]
bdev_disk_changed+0x936/0x1690 block/partitions/core.c:697
blkdev_get_whole+0x2f9/0x390 block/bdev.c:682
blkdev_get_by_dev+0x2da/0xa50 block/bdev.c:827
blkdev_open+0x128/0x2c0 block/fops.c:466
do_dentry_open+0x7f7/0xf90 fs/open.c:826
do_open fs/namei.c:3616 [inline]
path_openat+0x2718/0x2fb0 fs/namei.c:3750
do_filp_open+0x1df/0x400 fs/namei.c:3777
do_sys_openat2+0x14b/0x500 fs/open.c:1255
do_sys_open fs/open.c:1271 [inline]
__do_sys_openat fs/open.c:1287 [inline]
__se_sys_openat fs/open.c:1282 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1282
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f22ccd88407
RSP: 002b:00007ffd11a2c740 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f22ccc9a880 RCX: 00007f22ccd88407
RDX: 00000000000a0800 RSI: 000056477b5cfa90 RDI: ffffffffffffff9c
RBP: 000056477b5bf910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056477b5e8560
R13: 000056477b5d7410 R14: 0000000000000000 R15: 000056477b5e8560
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3945:
#0: ffff88802c8f6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
1 lock held by udevd/4180:
#0: ffff888020e7c518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x162/0xa50 block/bdev.c:820
2 locks held by syz-executor/4191:
#0: ffff888020a52118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf1/0x780 block/bdev.c:915
#1: ffff888020b0c468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xb50 drivers/block/loop.c:1366
3 locks held by kworker/u4:7/4309:
#0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475
#1: ffff8880b9027888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x517/0x810 kernel/sched/psi.c:891
#2: ffff8880b90280d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:946
2 locks held by syz-executor/5950:
#0: ffff88802361a0e0 (&type->s_umount_key#60){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
#1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
3 locks held by kworker/1:20/7558:
#0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc9000383fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
#2: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
2 locks held by syz.0.640/7637:
#0: ffff888020a44518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf1/0x780 block/bdev.c:915
#1: ffff888020aa8468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe1b/0xe60 kernel/hung_task.c:369
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4364 Comm: kworker/u4:10 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: loop0 loop_rootcg_workfn
RIP: 0010:mark_lock+0xa/0x320 kernel/locking/lockdep.c:4552
Code: 8d e8 ea 83 60 00 4c 89 f7 41 89 d9 e9 79 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 41 57 41 56 41 55 41 54 53 <50> 89 d5 49 89 f6 48 89 fb 49 bd 00 00 00 00 00 fc ff df 83 fa 08
RSP: 0018:ffffc900032af6c8 EFLAGS: 00000006
RAX: 0000000000000000 RBX: ffff88802c819dc0 RCX: ffffffff815d8f84
RDX: 0000000000000006 RSI: ffff88802c81a8b0 RDI: ffff88802c819dc0
RBP: ffffc900032af7c0 R08: ffffffff901cb1e7 R09: 1ffffffff203963c
R10: dffffc0000000000 R11: fffffbfff203963d R12: ffff88802c81a8d0
R13: 0000000000000000 R14: 1ffff11005903515 R15: ffff88802c81a8b0
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcbeef75158 CR3: 000000007e5b1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
mark_held_locks kernel/locking/lockdep.c:4193 [inline]
__trace_hardirqs_on_caller kernel/locking/lockdep.c:4219 [inline]
lockdep_hardirqs_on_prepare+0x380/0x7c0 kernel/locking/lockdep.c:4278
trace_hardirqs_on+0x67/0x80 kernel/trace/trace_preemptirq.c:49
raise_softirq+0xd9/0x160 kernel/softirq.c:715
blk_mq_raise_softirq block/blk-mq.c:653 [inline]
blk_mq_complete_request_remote+0x44b/0x5c0 block/blk-mq.c:674
blk_mq_complete_request+0x15/0xa0 block/blk-mq.c:690
loop_handle_cmd drivers/block/loop.c:2252 [inline]
loop_process_work+0x1ff0/0x24c0 drivers/block/loop.c:2275
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287