INFO: task udevd:4369 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:23120 pid: 4369 ppid: 3562 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 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+0x83b/0xe50 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+0xb05/0x1030 mm/filemap.c:3480
read_mapping_page include/linux/pagemap.h:515 [inline]
read_part_sector+0xd4/0x4f0 block/partitions/core.c:726
adfspart_check_ICS+0xc3/0xe40 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+0x933/0x16c0 block/partitions/core.c:697
blkdev_get_whole+0x2f9/0x390 block/bdev.c:682
blkdev_get_by_dev+0x2d0/0xa60 block/bdev.c:827
blkdev_open+0x12d/0x2c0 block/fops.c:466
do_dentry_open+0x7ff/0xf80 fs/open.c:826
do_open fs/namei.c:3616 [inline]
path_openat+0x26f5/0x2fa0 fs/namei.c:3750
do_filp_open+0x1e2/0x410 fs/namei.c:3777
do_sys_openat2+0x150/0x4b0 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: 0033:0x7f4743a31407
RSP: 002b:00007ffe64cf1ed0 EFLAGS: 00000202
ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4743943880 RCX: 00007f4743a31407
RDX: 00000000000a0800 RSI: 0000561294620570 RDI: ffffffffffffff9c
RBP: 000056129461f910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056129463cf10
R13: 0000561294637410 R14: 0000000000000000 R15: 000056129463cf10
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c31f360
(
rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
5 locks held by kworker/u4:5/1300:
#0: ffff8880197e8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc90004b1fd00 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffff888020b9d170 (&lo->lo_work_lock){....}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:389 [inline]
#2: ffff888020b9d170 (&lo->lo_work_lock){....}-{2:2}, at: loop_process_work+0x1ffb/0x24a0 drivers/block/loop.c:2278
#3: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:483
#4: ffffffff8c31f360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312
1 lock held by udevd/3562:
#0: ffff888020782118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
2 locks held by getty/3947:
#0: ffff88802cdc0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
1 lock held by udevd/4182:
#0: ffff888020782118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
1 lock held by syz-executor/4198:
#0: ffff888020785918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
5 locks held by kworker/0:8/4235:
1 lock held by udevd/4369:
#0:
ffff888020d5fd18
(
&disk->open_mutex
){+.+.}-{3:3}
, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
1 lock held by syz-executor/6111:
#0:
ffff888020b7c468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366
2 locks held by udevd/6331:
#0:
ffff888020785918
(
&disk->open_mutex
){+.+.}-{3:3}
, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
#1:
ffff8881474eb468
(
&lo->lo_mutex
){+.+.}-{3:3}
, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
3 locks held by syz.9.2883/16097:
#0:
ffff8880684b8460
(
sb_writers
#22
){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
#1: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:483
#2: ffff8880b9027888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4fe/0x7d0 kernel/sched/psi.c:891
2 locks held by syz.1.2910/16200:
#0: ffff888020782118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
#1: ffff888020a95468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
=============================================
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 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+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4182 Comm: udevd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:task_wait_context kernel/locking/lockdep.c:4626 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4707 [inline]
RIP: 0010:__lock_acquire+0x86e/0x7d10 kernel/locking/lockdep.c:4962
Code: 89 e6 65 8b 05 c7 43 a5 7e 41 b5 02 85 c0 48 8b 5c 24 40 4c 8b bc 24 98 00 00 00 75 24 48 8b 84 24 c0 00 00 00 42 0f b6 04 00 <84> c0 0f 85 d8 64 00 00 41 83 3f 00 41 0f 94 c5 45 00 ed 41 80 c5
RSP: 0018:ffffc90002e6fae0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880781b8ae8 RCX: 0000000000000003
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d8178
RBP: ffffc90002e6fd30 R08: dffffc0000000000 R09: 1ffffffff203b02f
R10: dffffc0000000000 R11: fffffbfff203b030 R12: 0000000000000000
R13: ffff8880781b8b02 R14: 0000000000000000 R15: ffff8880781b8ad4
FS: 00007f4743943880(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4742ff7000 CR3: 000000001f6d1000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
down_write+0x38/0x60 kernel/locking/rwsem.c:1551
inode_lock include/linux/fs.h:787 [inline]
blkdev_llseek+0x69/0xb0 block/fops.c:417
vfs_llseek fs/read_write.c:300 [inline]
ksys_lseek fs/read_write.c:313 [inline]
__do_sys_lseek fs/read_write.c:324 [inline]
__se_sys_lseek fs/read_write.c:322 [inline]
__x64_sys_lseek+0x169/0x1f0 fs/read_write.c:322
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: 0033:0x7f4743a9ebe7
Code: 66 89 04 24 31 c0 e8 68 cc ff ff 48 83 c4 20 5b c3 48 8b 05 03 c2 0d 00 64 c7 00 0d 00 00 00 eb b0 66 90 b8 08 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 e1 c1 0d 00 f7 d8 64 89 02 48
RSP: 002b:00007ffe64ceca78 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
RAX: ffffffffffffffda RBX: 0000000000000400 RCX: 00007f4743a9ebe7
RDX: 0000000000000000 RSI: 0000000000fff000 RDI: 0000000000000009
RBP: 000056129462d050 R08: 0000000000000000 R09: 0000000000000000
R10: 000056129462d0b0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000fff000 R14: 000056129462d0b0 R15: 0000000000040000