INFO: task udevd:4301 blocked for more than 143 seconds. Not tainted 5.15.187-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24768 pid: 4301 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 device_lock include/linux/device.h:760 [inline] uevent_show+0x17a/0x330 drivers/base/core.c:2408 dev_attr_show+0x50/0xb0 drivers/base/core.c:2110 sysfs_kf_seq_show+0x316/0x4c0 fs/sysfs/file.c:61 seq_read_iter+0x49b/0xd50 fs/seq_file.c:230 call_read_iter include/linux/fs.h:2166 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x725/0xcf0 fs/read_write.c:485 ksys_read+0x14d/0x250 fs/read_write.c:623 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: 0033:0x7fd0d4566407 RSP: 002b:00007ffd3dc89cb0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fd0d4478880 RCX: 00007fd0d4566407 RDX: 0000000000001000 RSI: 00005609828d9a10 RDI: 0000000000000008 RBP: 00007fd0d46aeff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007fd0d46aeea0 R14: 0000000000000000 R15: 00005609828cdbe0 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c2e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by pvrusb2-context/2425: #0: ffff88807afa0188 (&hdw->big_lock_mutex){+.+.}-{3:3}, at: pvr2_hdw_initialize+0xc3/0x3a80 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2326 #1: ffffffff8bfccb70 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xe7/0x320 kernel/umh.c:217 2 locks held by getty/3950: #0: ffff88802bfca098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 2 locks held by syz-executor/4191: #0: ffff888020409918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff888020568468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 3 locks held by kworker/0:7/4239: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000323fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c120d68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8c120d68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x6b0 kernel/rcu/tree_exp.h:845 4 locks held by udevd/4301: #0: ffff88807ccee790 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff88805ea52088 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112 #2: ffff8880673293a8 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3c0 fs/kernfs/file.c:113 #3: ffff888022cd9220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #3: ffff888022cd9220 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17a/0x330 drivers/base/core.c:2408 6 locks held by kworker/1:17/4787: #0: ffff8881425ed938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003c8fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff888147e61220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #2: ffff888147e61220 (&dev->mutex){....}-{3:3}, at: hub_event+0x18f/0x4fa0 drivers/usb/core/hub.c:5781 #3: ffff888022cd9220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #3: ffff888022cd9220 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x107/0x8a0 drivers/usb/core/hub.c:2250 #4: ffff88805741a1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #4: ffff88805741a1a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline] #4: ffff88805741a1a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb0/0x750 drivers/base/dd.c:1259 #5: ffff88807afa0188 (&hdw->big_lock_mutex){+.+.}-{3:3}, at: pvr2_hdw_disconnect+0x69/0x500 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2710 3 locks held by kworker/1:20/4876: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003d3fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88801eec7240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480 1 lock held by syz-executor/9761: #0: ffffffff8c120d68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8c120d68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 1 lock held by syz.5.865/10026: #0: ffff888055026e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #0: ffff888055026e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:648 [inline] #0: ffff888055026e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1336 1 lock held by dhcpcd/10085: #0: ffff888051ab0120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1694 [inline] #0: ffff888051ab0120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xce0 net/packet/af_packet.c:3213 1 lock held by rm/10097: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.187-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3560 Comm: udevd Not tainted 5.15.187-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:vsnprintf+0x125/0x1a00 lib/vsprintf.c:2770 Code: 44 0f b6 e3 4c 89 e7 48 c7 c6 80 bb 73 8c e8 22 55 79 fd 41 80 fc 12 0f 87 ce 03 00 00 42 ff 24 e5 20 bb 5c 8a 4c 8b 64 24 10 <4d> 39 e5 0f 83 2b 0c 00 00 e8 9d 50 79 fd 4c 89 e0 4c 29 e8 4c 39 RSP: 0018:ffffc90002e9f3b0 EFLAGS: 00000297 RAX: 0000000000000012 RBX: ffff0a00ffffff00 RCX: 0000000000000001 RDX: ffffffff83fe825e RSI: ffffffff8c73bb80 RDI: 0000000000000000 RBP: ffffffff8a5359ab R08: ffff88807dbf5940 R09: 0000000000000012 R10: 0000000000000012 R11: 0000000000000000 R12: ffffc90002e9f541 R13: ffffc90002e9f575 R14: 0000000000000001 R15: ffffffff8a5359aa FS: 00007fd0d4478880(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555592dc3608 CR3: 000000007ce80000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tomoyo_supervisor+0x143/0x10d0 security/tomoyo/common.c:2069 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission+0x25a/0x380 security/tomoyo/file.c:587 tomoyo_check_open_permission+0x216/0x360 security/tomoyo/file.c:777 security_file_open+0x5e/0xa0 security/security.c:1668 do_dentry_open+0x322/0xf80 fs/open.c:813 do_open fs/namei.c:3608 [inline] path_openat+0x2682/0x2f30 fs/namei.c:3742 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 do_sys_openat2+0x142/0x4a0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 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: 0033:0x7fd0d45d4c3a Code: 41 89 f2 48 89 54 24 e0 41 83 e2 40 75 2a 89 f0 f7 d0 a9 00 00 41 00 74 1f 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 77 2e c3 0f 1f 44 00 00 48 8d 44 24 08 c7 44 24 RSP: 002b:00007ffd3dc928c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000560982901ae0 RCX: 00007fd0d45d4c3a RDX: 0000000000090800 RSI: 00005609828cd1d0 RDI: 00000000ffffff9c RBP: 00005609828cd1d0 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000206 R12: 00005609828d57c0 R13: 00000000000000ff R14: 000056095ee3fbe0 R15: 00007ffd3dc92b50