INFO: task udevd:2857 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:23704 pid:2857 tgid:2857 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1138/0x47e0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
rwsem_down_read_slowpath+0x5af/0xb40 kernel/locking/rwsem.c:1114
__down_read_common kernel/locking/rwsem.c:1291 [inline]
__down_read kernel/locking/rwsem.c:1304 [inline]
down_read+0xed/0x450 kernel/locking/rwsem.c:1570
kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218
d_revalidate fs/namei.c:1030 [inline]
d_revalidate fs/namei.c:1026 [inline]
lookup_fast+0x3c7/0x600 fs/namei.c:1876
walk_component fs/namei.c:2274 [inline]
link_path_walk+0x7d4/0x1cc0 fs/namei.c:2652
path_lookupat+0x74/0xc40 fs/namei.c:2808
filename_lookup+0x202/0x590 fs/namei.c:2838
do_readlinkat+0xd3/0x370 fs/stat.c:571
__do_sys_readlink fs/stat.c:605 [inline]
__se_sys_readlink fs/stat.c:602 [inline]
__x64_sys_readlink+0x78/0xc0 fs/stat.c:602
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f76ce06c3a7
RSP: 002b:00007ffc84c882f8 EFLAGS: 00000246
ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffc84c887d0 RCX: 00007f76ce06c3a7
RDX: 0000000000000400 RSI: 00007ffc84c88300 RDI: 00007ffc84c887d0
RBP: 00007ffc84c88300 R08: 0000000000000075 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400
R13: 00005627c5949100 R14: 0000000000000001 R15: 00007ffc84c8a0d0
Showing all locks held in the system:
1 lock held by ksoftirqd/1/22:
1 lock held by khungtaskd/30:
#0: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:4/62:
#0: ffff888100e98940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
#1: ffffc900005a7d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
#2: ffffffff8aadc468 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
#3: ffffffff896ea4a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by getty/2920:
#0: ffff8881129c80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900000452e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
6 locks held by kworker/0:3/5232:
#0: ffff8881062b1140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
#1: ffffc90001f4fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
#2: ffff88810c34b1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#2: ffff88810c34b1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff88810ffa61d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#3: ffff88810ffa61d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336
#4: ffff88810ffa71a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#4: ffff88810ffa71a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
#4: ffff88810ffa71a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1372
#5: ffffffff8a515a20 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#5: ffffffff8a515a20 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x156/0x470 drivers/input/input.c:2204
4 locks held by udevd/5242:
#0: ffff888108b9b518 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff888119ee2080 (&of->mutex){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2: ffff88811e48a2d8 (kn->active#26){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88811e48a2d8 (kn->active#26){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
#3: ffff88810ffa61d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline]
#3: ffff88810ffa61d8 (&dev->mutex){....}-{4:4}, at: serial_show+0x26/0xa0 drivers/usb/core/sysfs.c:143
6 locks held by kworker/0:5/5255:
#0: ffff8881062b1140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
#1: ffffc90001edfd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
#2: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#2: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
#2: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
#3: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:652 [inline]
#3: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1624 [inline]
#3: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1968 [inline]
#3: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x2bc/0x47e0 kernel/sched/core.c:7064
#4: ffffffff94061388 (&____s->seqcount){----}-{0:0}, at: hrtimer_update_base kernel/time/hrtimer.c:683 [inline]
#4: ffffffff94061388 (&____s->seqcount){----}-{0:0}, at: hrtimer_interrupt+0x3fe/0x940 kernel/time/hrtimer.c:2125
#5: ffffffff94061388 (&____s->seqcount){----}-{0:0}, at: clockevents_program_event+0x23e/0x820 kernel/time/clockevents.c:363
2 locks held by syz-executor/6419:
2 locks held by syz-executor/6420:
2 locks held by syz-executor/6427:
2 locks held by syz-executor/6434:
2 locks held by syz-executor/6438:
2 locks held by modprobe/6440:
#0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:652 [inline]
#0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1624 [inline]
#0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1968 [inline]
#0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x2bc/0x47e0 kernel/sched/core.c:7064
#1: ffff8881f5628158 (hrtimer_bases.lock){-.-.}-{2:2}, at: lock_hrtimer_base kernel/time/hrtimer.c:191 [inline]
#1: ffff8881f5628158 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_start_range_ns+0xeb/0x1a50 kernel/time/hrtimer.c:1489
2 locks held by modprobe/6442:
#0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:652 [inline]
#0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1624 [inline]
#0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1968 [inline]
#0: ffff8881f56396e0 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x2bc/0x47e0 kernel/sched/core.c:7064
#1: ffff8881229ca518 (&sighand->siglock){....}-{3:3}, at: do_notify_parent+0x78c/0x10b0 kernel/signal.c:2229
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 2839 Comm: syslogd Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:unix_skb_to_scm net/unix/af_unix.c:2005 [inline]
RIP: 0010:__unix_dgram_recvmsg+0x4ee/0xc30 net/unix/af_unix.c:2638
Code: c8 00 00 00 48 89 c7 48 89 44 24 40 e8 7b 8e 61 fb 49 8d 7f 28 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 05 07 00 00 49 8d 7f 30 4d 8b 77 28 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc9000206fa50 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffff888116500880 RCX: 0000000000000000
RDX: 1ffff1102277e7bd RSI: 0000000000000000 RDI: ffff888113bf3de8
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc9000206fb18 R11: 0000000000000000 R12: ffff888116500e00
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888113bf3dc0
FS: 00007fae86da1c80(0000) GS:ffff8882687a5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fde9d605e9c CR3: 00000001166b6000 CR4: 00000000003506f0
Call Trace:
unix_dgram_recvmsg+0xcd/0x100 net/unix/af_unix.c:2686
sock_recvmsg_nosec net/socket.c:1137 [inline]
sock_recvmsg+0x1a4/0x1f0 net/socket.c:1159
sock_read_iter+0x2c6/0x3c0 net/socket.c:1229
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x957/0xb30 fs/read_write.c:574
ksys_read+0x1f8/0x250 fs/read_write.c:717
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fae86ef1407
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:00007ffe2cdfc300 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fae86da1c80 RCX: 00007fae86ef1407
RDX: 00000000000000ff RSI: 0000564e44332300 RDI: 0000000000000000
RBP: 0000564e443322c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000564e44332380
R13: 0000000000000000 R14: 0000564e44332300 R15: 0000564e3e908d98