INFO: task udevd:5799 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:24584 pid:5799 ppid:5159 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
folio_put_wait_locked mm/filemap.c:1493 [inline]
do_read_cache_folio+0x1c0/0x7e0 mm/filemap.c:3771
read_mapping_folio include/linux/pagemap.h:898 [inline]
read_part_sector+0xd2/0x350 block/partitions/core.c:718
adfspart_check_POWERTEC+0x8d/0xf00 block/partitions/acorn.c:454
check_partition block/partitions/core.c:138 [inline]
blk_add_partitions block/partitions/core.c:600 [inline]
bdev_disk_changed+0x73a/0x1410 block/partitions/core.c:689
blkdev_get_whole+0x30d/0x390 block/bdev.c:655
blkdev_get_by_dev+0x279/0x600 block/bdev.c:797
blkdev_open+0x152/0x360 block/fops.c:589
do_dentry_open+0x8c6/0x1500 fs/open.c:929
do_open fs/namei.c:3632 [inline]
path_openat+0x274b/0x3190 fs/namei.c:3789
do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
do_sys_open fs/open.c:1434 [inline]
__do_sys_openat fs/open.c:1450 [inline]
__se_sys_openat fs/open.c:1445 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1445
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb6ee2a7407
RSP: 002b:00007fff2ffc9530 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb6eea6a880 RCX: 00007fb6ee2a7407
RDX: 00000000000a0800 RSI: 000056168c05d0f0 RDI: ffffffffffffff9c
RBP: 000056168c045910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056168c059ba0
R13: 000056168c05d410 R14: 0000000000000000 R15: 000056168c059ba0
</TASK>
INFO: task udevd:5801 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:23976 pid:5801 ppid:5159 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
folio_put_wait_locked mm/filemap.c:1493 [inline]
do_read_cache_folio+0x1c0/0x7e0 mm/filemap.c:3771
read_mapping_folio include/linux/pagemap.h:898 [inline]
read_part_sector+0xd2/0x350 block/partitions/core.c:718
adfspart_check_POWERTEC+0x8d/0xf00 block/partitions/acorn.c:454
check_partition block/partitions/core.c:138 [inline]
blk_add_partitions block/partitions/core.c:600 [inline]
bdev_disk_changed+0x73a/0x1410 block/partitions/core.c:689
blkdev_get_whole+0x30d/0x390 block/bdev.c:655
blkdev_get_by_dev+0x279/0x600 block/bdev.c:797
blkdev_open+0x152/0x360 block/fops.c:589
do_dentry_open+0x8c6/0x1500 fs/open.c:929
do_open fs/namei.c:3632 [inline]
path_openat+0x274b/0x3190 fs/namei.c:3789
do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
do_sys_open fs/open.c:1434 [inline]
__do_sys_openat fs/open.c:1450 [inline]
__se_sys_openat fs/open.c:1445 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1445
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb6ee2a7407
RSP: 002b:00007fff2ffc9530 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb6eea6a880 RCX: 00007fb6ee2a7407
RDX: 00000000000a0800 RSI: 000056168c058a40 RDI: ffffffffffffff9c
RBP: 000056168c045910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056168c059ba0
R13: 000056168c05d410 R14: 0000000000000000 R15: 000056168c059ba0
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:4/58:
#0: ffff88802c223138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88802c223138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90001597d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90001597d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8dfbc348 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4700
2 locks held by kworker/0:3/5174:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003297d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003297d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by dhcpcd/5455:
#0: ffffffff8dfbc348 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x32c/0x1c60 net/ipv4/devinet.c:1102
2 locks held by getty/5551:
#0: ffff888030dea0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by udevd/5799:
#0: ffff888140fe94c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
1 lock held by udevd/5801:
#0: ffff888021f6b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
1 lock held by udevd/6081:
#0: ffff8881476d34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
5 locks held by kworker/u4:12/6420:
#0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000c9cfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000c9cfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8dfaf510 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606
#3: ffff88804aefd3e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x116/0x310 drivers/net/wireguard/device.c:250
#4: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#4: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
3 locks held by kworker/u4:14/6422:
#0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000c9dfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000c9dfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8dfbc348 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
2 locks held by syz-executor/7430:
#0: ffffffff8dfbc348 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8dfbc348 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472
#1: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
1 lock held by syz.6.353/7521:
#0: ffffffff8dfbc348 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8dfbc348 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: rcu_gp process_srcu
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:preempt_count_sub+0x37/0x160 kernel/sched/core.c:5872
Code: fc ff df 48 c7 c0 80 c4 ea 96 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 bd 00 00 00 83 3d c2 58 8f 15 00 75 25 65 8b 05 41 4e a8 7e <89> c1 81 e1 ff ff ff 7f 39 cf 7f 25 81 ff ff 00 00 00 0f 93 c1 84
RSP: 0018:ffffc900000e79e8 EFLAGS: 00000246
RAX: 0000000080000001 RBX: dffffc0000000000 RCX: ffffffff96eac403
RDX: 00000000000000eb RSI: ffffffff8afc7020 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff8880b8f43f8f R09: 1ffff110171e87f1
R10: dffffc0000000000 R11: ffffed10171e87f2 R12: 0000000000000002
R13: ffff8880b8f43f88 R14: 000000ebae3a4dfa R15: 0000000000000ece
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9d34794198 CR3: 0000000074d35000 CR4: 00000000003506f0
Call Trace:
<TASK>
delay_tsc+0x4e/0xc0 arch/x86/lib/delay.c:77
try_check_zero+0x39a/0x3e0 kernel/rcu/srcutree.c:1090
srcu_advance_state kernel/rcu/srcutree.c:1692 [inline]
process_srcu+0x243/0x1330 kernel/rcu/srcutree.c:1795
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>