INFO: task udevd:2382 blocked for more than 143 seconds. Not tainted 6.6.0-rc6-syzkaller-00169-gc70793fb7632 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:26576 pid:2382 ppid:1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xc79/0x30a0 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6830 rwsem_down_read_slowpath+0x61e/0xb20 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1250 [inline] __down_read kernel/locking/rwsem.c:1263 [inline] down_read+0xf0/0x470 kernel/locking/rwsem.c:1522 kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138 d_revalidate fs/namei.c:861 [inline] d_revalidate fs/namei.c:858 [inline] lookup_fast+0x232/0x520 fs/namei.c:1654 walk_component+0x5b/0x5a0 fs/namei.c:1997 link_path_walk.part.0.constprop.0+0x71f/0xce0 fs/namei.c:2328 link_path_walk fs/namei.c:2253 [inline] path_openat+0x231/0x29c0 fs/namei.c:3792 do_filp_open+0x1de/0x430 fs/namei.c:3823 do_sys_openat2+0x176/0x1e0 fs/open.c:1422 do_sys_open fs/open.c:1437 [inline] __do_sys_openat fs/open.c:1453 [inline] __se_sys_openat fs/open.c:1448 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1448 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f9732e6c9a4 RSP: 002b:00007ffca424a1c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f9732e6c9a4 RDX: 0000000000080000 RSI: 00007ffca424a2f8 RDI: 00000000ffffff9c RBP: 00007ffca424a2f8 R08: 0000000000000008 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000 R13: 000055cf111afb42 R14: 0000000000000001 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff87eac860 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline] #0: ffffffff87eac860 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:749 [inline] #0: ffffffff87eac860 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 4 locks held by kworker/0:2/584: 1 lock held by udevd/2382: #0: ffff888101657948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138 2 locks held by getty/2440: #0: ffff8881133c00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc5/0x1480 drivers/tty/n_tty.c:2206 3 locks held by syz-fuzzer/2497: 3 locks held by syz-fuzzer/5277: 1 lock held by syz-executor.1/2501: 1 lock held by syz-executor.0/2506: 2 locks held by kworker/0:5/5316: 3 locks held by kworker/0:6/5346: 4 locks held by kworker/1:5/5354: #0: ffff88810aa71538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc9000213fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 #2: ffff8881067d0190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] #2: ffff8881067d0190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5791 #3: ffff888101657948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_remove_by_name_ns+0x87/0x120 fs/kernfs/dir.c:1668 3 locks held by kworker/0:8/11521: 6 locks held by kworker/1:7/15127: #0: ffff88810aa71538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc9000fb6fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 #2: ffff8881067a5190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] #2: ffff8881067a5190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5791 #3: ffff888118878190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] #3: ffff888118878190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x10a/0x910 drivers/usb/core/hub.c:2251 #4: ffff8881135ba160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] #4: ffff8881135ba160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff8881135ba160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 #5: ffff888101657948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_remove_by_name_ns+0x87/0x120 fs/kernfs/dir.c:1668 5 locks held by kworker/u4:1/17220: #0: ffff888100073d38 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc9000f097d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 #2: ffffffff88f96f90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9f/0xb20 net/core/net_namespace.c:576 #3: ffffffff88fac028 (rtnl_mutex){+.+.}-{3:3}, at: sit_exit_batch_net+0x8c/0x580 net/ipv6/sit.c:1883 #4: ffff888101657948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_remove_by_name_ns+0x87/0x120 fs/kernfs/dir.c:1668 5 locks held by kworker/0:1/17617: 1 lock held by udevd/18423: #0: ffff888101657948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138 1 lock held by syz-executor.5/21737: 1 lock held by syz-executor.2/21738: #0: ffff888101657948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_remove_by_name_ns+0x87/0x120 fs/kernfs/dir.c:1668 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.0-rc6-syzkaller-00169-gc70793fb7632 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x26c/0x2d0 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+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5346 Comm: kworker/0:6 Not tainted 6.6.0-rc6-syzkaller-00169-gc70793fb7632 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Workqueue: events_power_efficient gc_worker RIP: 0010:__lock_acquire+0x31a/0x5de0 kernel/locking/lockdep.c:5072 Code: 02 00 0f 85 6d 3e 00 00 49 8d 45 18 4d 89 55 10 48 89 c2 48 89 44 24 50 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 5e 3e 00 00 48 ba 00 00 00 00 00 fc ff df 48 8b 0c 24 48 8b RSP: 0018:ffffc9000214f990 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 000000000000001f RCX: 1ffff1102306d15e RDX: 1ffff1102306d15d RSI: 0000000000000318 RDI: ffff888118368ad8 RBP: 0000000000000000 R08: 1ffff1102306d159 R09: 0000000000000001 R10: ffffffff87eac860 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888118368ad0 R14: 0000000000000000 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8881f6600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fb25000 CR3: 0000000007c9b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718 rcu_lock_acquire include/linux/rcupdate.h:303 [inline] rcu_read_lock include/linux/rcupdate.h:749 [inline] gc_worker+0x24d/0x17d0 net/netfilter/nf_conntrack_core.c:1488 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304