INFO: task udevd:20018 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:22568 pid:20018 tgid:20018 ppid:5233 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
io_schedule+0x80/0xd0 kernel/sched/core.c:7906
folio_wait_bit_common+0x6b0/0xb80 mm/filemap.c:1330
folio_put_wait_locked mm/filemap.c:1494 [inline]
do_read_cache_folio+0x1aa/0x590 mm/filemap.c:3991
read_mapping_folio include/linux/pagemap.h:999 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
adfspart_check_POWERTEC+0x8c/0xf30 block/partitions/acorn.c:454
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:748
bdev_open+0x31e/0xd30 block/bdev.c:957
blkdev_open+0x457/0x600 block/fops.c:694
do_dentry_open+0x953/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4134
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f84d44a7407
RSP: 002b:00007ffd25a9dd00 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f84d4c68880 RCX: 00007f84d44a7407
RDX: 00000000000a0800 RSI: 00005610b5ed1a10 RDI: ffffffffffffff9c
RBP: 00005610b5ec1910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005610b5ef40d0
R13: 00005610b5ecf190 R14: 0000000000000000 R15: 00005610b5ef40d0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e53d360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53d360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e53d360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5623:
#0: ffff88814d8370a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/20018:
#0: ffff888025e6e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.9.11786/18681:
#0: ffffffff8e542df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e542df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
1 lock held by syz-executor/19115:
#0: ffffffff8e542df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8e542df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
=============================================
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+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
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: 18598 Comm: syz.5.11768 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:validate_chain+0x2c4/0x2140 kernel/locking/lockdep.c:3920
Code: 00 00 83 3d 4d 2e 46 0e 00 0f 84 a2 17 00 00 b8 01 00 00 00 65 48 8b 0d ea 98 47 11 48 3b 8c 24 d8 00 00 00 0f 85 43 1c 00 00 <48> 81 c4 e0 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d e9 46 6d eb 09
RSP: 0018:ffffc9000bce7328 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ef9e850eef103800
RDX: 0000000000000001 RSI: ffff8880283e2970 RDI: ffff8880283e1e40
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81cf8696
R10: ffffc9000bce7658 R11: ffffffff81ad1660 R12: 0000000000004008
R13: ffff8880283e2970 R14: ffff8880283e2970 R15: 0ac0d5affe09d4ff
FS: 0000000000000000(0000) GS:ffff8881257be000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4c48117d60 CR3: 000000000e338000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000000000000ee
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
is_bpf_text_address+0x47/0x2b0 kernel/bpf/core.c:744
kernel_text_address+0xa5/0xe0 kernel/extable.c:125
__kernel_text_address+0xd/0x40 kernel/extable.c:79
unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369
arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
__free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906
vfree+0x25a/0x400 mm/vmalloc.c:3440
kcov_put kernel/kcov.c:439 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:535
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:966
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 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+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb9bc5c1785
Code: Unable to access opcode bytes at 0x7fb9bc5c175b.
RSP: 002b:00007fb9bd3fcf80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007fb9bc7e5fa0 RCX: 00007fb9bc5c1785
RDX: 00007fb9bd3fcfc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fb9bc611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007fb9bc7e6038 R14: 00007fb9bc7e5fa0 R15: 00007fffa5e7bc48