INFO: task udevd:7081 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:23584 pid:7081 ppid:3637 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 device_lock include/linux/device.h:840 [inline] uevent_show+0x16c/0x320 drivers/base/core.c:2669 dev_attr_show+0x50/0xb0 drivers/base/core.c:2372 sysfs_kf_seq_show+0x349/0x4b0 fs/sysfs/file.c:59 seq_read_iter+0x49b/0xd50 fs/seq_file.c:230 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x434/0x920 fs/read_write.c:470 ksys_read+0x143/0x240 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa438dc8407 RSP: 002b:00007ffd0b2145e0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fa43879b880 RCX: 00007fa438dc8407 RDX: 0000000000001000 RSI: 0000556f93751a00 RDI: 0000000000000008 RBP: 00007fa438f10ff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007fa438f10ea0 R14: 0000000000000000 R15: 0000556f9375a080 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2be50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 6 locks held by kworker/1:0/22: #0: ffff88801aae0138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900001c7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff888027ab4190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #2: ffff888027ab4190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x54e0 drivers/usb/core/hub.c:5845 #3: ffff888078cb2190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #3: ffff888078cb2190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x107/0x8a0 drivers/usb/core/hub.c:2305 #4: ffff88801d6df118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #4: ffff88801d6df118 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1080 [inline] #4: ffff88801d6df118 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb2/0x850 drivers/base/dd.c:1283 #5: ffff8880242f8188 (&hdw->big_lock_mutex){+.+.}-{3:3}, at: pvr2_hdw_disconnect+0x69/0x500 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2710 1 lock held by khungtaskd/27: #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 6 locks held by kworker/u4:3/51: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000bc7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd34b90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffff8880572722f8 (&devlink->lock_key){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0xf8/0x270 net/devlink/leftover.c:12500 #4: ffffffff8dd41868 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381 #5: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #5: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 3 locks held by kworker/0:2/126: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90002d97d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff88807cc1a240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26b/0x32b0 drivers/net/netdevsim/fib.c:1491 2 locks held by pvrusb2-context/2309: #0: ffff8880242f8188 (&hdw->big_lock_mutex){+.+.}-{3:3}, at: pvr2_hdw_initialize+0xc3/0x3a80 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2326 #1: ffffffff8c9d7850 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xec/0x2a0 kernel/umh.c:218 2 locks held by dhcpcd/3931: #0: ffffffff8dd27968 (vlan_ioctl_mutex){+.+.}-{3:3}, at: sock_ioctl+0x273/0x6e0 net/socket.c:1283 #1: ffffffff8dd41868 (rtnl_mutex){+.+.}-{3:3}, at: vlan_ioctl_handler+0xd2/0x5f0 net/8021q/vlan.c:578 2 locks held by getty/4026: #0: ffff88814d978098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 2 locks held by kworker/0:8/4346: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004187d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 4 locks held by udevd/7081: #0: ffff88801fe512f0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff8880268fac88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x58/0x410 fs/kernfs/file.c:172 #2: ffff88801eb5c0f0 (kn->active#5){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88801eb5c0f0 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173 #3: ffff888078cb2190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #3: ffff888078cb2190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2669 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4642 Comm: kworker/u4:16 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: phy8 ieee80211_iface_work RIP: 0010:ieee80211_update_sta_info net/mac80211/ibss.c:-1 [inline] RIP: 0010:ieee80211_rx_bss_info net/mac80211/ibss.c:1118 [inline] RIP: 0010:ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1609 [inline] RIP: 0010:ieee80211_ibss_rx_queued_mgmt+0x1053/0x2b10 net/mac80211/ibss.c:1638 Code: 08 48 8d 1c 83 49 89 df 49 c1 ef 03 49 bc 00 00 00 00 00 fc ff df 43 0f b6 04 27 84 c0 0f 85 b4 14 00 00 48 89 5c 24 40 8b 03 <89> 44 24 60 48 8b 44 24 28 48 8d 58 47 4c 8d 70 48 48 89 d8 48 c1 RSP: 0018:ffffc90004e3f8e0 EFLAGS: 00000246 RAX: 0000000000000fff RBX: ffff888054bb0fe8 RCX: ffff88802500bb80 RDX: 0000000000000000 RSI: ffff88807a1c620e RDI: 0000000000000040 RBP: ffffc90004e3fbb8 R08: dffffc0000000000 R09: fffffbfff1c3ed96 R10: fffffbfff1c3ed96 R11: 1ffffffff1c3ed95 R12: dffffc0000000000 R13: ffff88807ded5af8 R14: ffff888054bb0000 R15: 1ffff1100a9761fd FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005645e04a0000 CR3: 000000007e47e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ieee80211_iface_process_skb net/mac80211/iface.c:1671 [inline] ieee80211_iface_work+0x726/0xc80 net/mac80211/iface.c:1725 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295