INFO: task udevd:4753 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: 4753 ppid: 3560 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: 0033:0x7f3cf80e0407
RSP: 002b:00007ffdaf63ce90 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3cf7ff2880 RCX: 00007f3cf80e0407
RDX: 00000000000a0800 RSI: 000055b288717060 RDI: ffffffffffffff9c
RBP: 000055b288704910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055b288718ba0
R13: 000055b28871c410 R14: 0000000000000000 R15: 000055b288718ba0
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
2 locks held by getty/3950:
#0: ffff88807f463098 (&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+0x5df/0x1a70 drivers/tty/n_tty.c:2158
3 locks held by kworker/u4:4/4231:
1 lock held by udevd/4753:
#0: ffff88802092e518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
1 lock held by udevd/5726:
3 locks held by kworker/1:20/6752:
1 lock held by syz.9.4151/17389:
#0: ffff88802092e518 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1ab/0x320 block/bdev.c:1053
=============================================
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+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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4752 Comm: udevd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:format_decode+0x12c/0x1300 lib/vsprintf.c:2545
Code: 84 c0 0f 85 f2 0d 00 00 48 8b 04 24 4c 89 30 48 8b 6c 24 38 49 89 ee 48 89 e8 48 c1 e8 03 0f b6 04 18 84 c0 75 2b 45 0f b6 3e <4c> 89 ff 48 c7 c6 60 ec 93 8c e8 15 de 71 fd 45 85 ff 74 2d 41 83
RSP: 0018:ffffc900033df410 EFLAGS: 00000246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff8880185d8000
RDX: 0000000000000000 RSI: ffffffff8c93ec60 RDI: 000000000000002e
RBP: ffffffff8a2be806 R08: ffff8880185d8000 R09: 0000000000000002
R10: 0000000000000025 R11: 0000000000000000 R12: ffffc900833df75f
R13: ffff0a0000000509 R14: ffffffff8a2be806 R15: 0000000000000025
FS: 00007f3cf7ff2880(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff5002f8a10 CR3: 0000000053e4a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
vsnprintf+0xef/0x1c20 lib/vsprintf.c:2763
sprintf+0xe4/0x140 lib/vsprintf.c:3013
print_time kernel/printk/printk.c:1274 [inline]
info_print_prefix+0x168/0x360 kernel/printk/printk.c:1300
record_print_text kernel/printk/printk.c:1349 [inline]
console_unlock+0x66e/0x1120 kernel/printk/printk.c:2725
vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
devkmsg_emit+0xe1/0x130 kernel/printk/printk.c:649
devkmsg_write+0x335/0x3f0 kernel/printk/printk.c:712
do_iter_readv_writev+0x47e/0x5f0 fs/read_write.c:-1
do_iter_write+0x205/0x7b0 fs/read_write.c:855
vfs_writev fs/read_write.c:928 [inline]
do_writev+0x281/0x480 fs/read_write.c:971
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: 0033:0x7f3cf80e0407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffdaf63bfb0 EFLAGS: 00000202 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f3cf7ff2880 RCX: 00007f3cf80e0407
RDX: 0000000000000005 RSI: 00007ffdaf63c070 RDI: 0000000000000005
RBP: 00007ffdaf63c1a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffdaf63c070
R13: 00007ffdaf63c100 R14: 0000000000000000 R15: 00007ffdaf63c0e0