INFO: task udevd:4176 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:23344 pid: 4176 ppid: 3558 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:678
blkdev_get_by_dev+0x2da/0xa50 block/bdev.c:823
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: 0033:0x7f2dadf42407
RSP: 002b:00007ffeec3923d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f2dade54880 RCX: 00007f2dadf42407
RDX: 00000000000a0800 RSI: 0000564509d65460 RDI: ffffffffffffff9c
RBP: 0000564509d3f910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000564509d52e20
R13: 0000564509d57410 R14: 0000000000000000 R15: 0000564509d52e20
Showing all locks held in the system:
2 locks held by kworker/u4:0/9:
#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
1 lock held by khungtaskd/27:
#0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by dhcpcd/3851:
#0: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x256/0x1ba0 net/ipv4/devinet.c:1076
2 locks held by getty/3946:
#0: ffff88814cd17098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
1 lock held by udevd/4176:
#0: ffff888020848518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x162/0xa50 block/bdev.c:816
4 locks held by udevd/4180:
#0: ffff8880684e10a0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182
#1: ffff88805eea8c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:112
#2: ffff888060d4acb8 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:113
#3: ffff8880616f01a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#3: ffff8880616f01a8 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2408
3 locks held by kworker/u4:6/4253:
#0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc9000312fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
3 locks held by kworker/0:16/5357:
#0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc90003effd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
#2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
2 locks held by kworker/0:18/5360:
#0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc90003f2fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
5 locks held by kworker/0:22/8349:
#0: ffff8880183d3138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc90003defd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffff888024339220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#2: ffff888024339220 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5260 drivers/usb/core/hub.c:5827
#3: ffff8880603cb220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#3: ffff8880603cb220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:974
#4: ffff8880616f01a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#4: ffff8880616f01a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:974
3 locks held by kworker/0:24/8539:
#0: ffff88802b182938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc900033cfd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4120
1 lock held by syz.7.1610/11731:
#0: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
#0: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3443
2 locks held by syz.1.1613/11745:
#0: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
#0: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3443
#1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
=============================================
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 07/24/2026
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