INFO: task udevd:4185 blocked for more than 143 seconds. Not tainted 5.15.186-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23168 pid: 4185 ppid: 3547 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: 0033:0x7f278839d407 RSP: 002b:00007ffc496dd970 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f27882af880 RCX: 00007f278839d407 RDX: 0000000000001000 RSI: 00005575b71dffc0 RDI: 0000000000000008 RBP: 00007f27884e5ff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007f27884e5ea0 R14: 0000000000000000 R15: 00005575b71da050 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: #0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90000ce7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d21eb90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589 #3: ffffffff8d22a808 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0x86b/0xa40 net/core/dev.c:10696 1 lock held by khungtaskd/27: #0: ffffffff8c11bfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 3 locks held by kworker/0:2/1107: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000492fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff888060876240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480 2 locks held by pvrusb2-context/2426: #0: ffff888065d88188 (&hdw->big_lock_mutex){+.+.}-{3:3}, at: pvr2_hdw_initialize+0xc3/0x3a80 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2326 #1: ffffffff8bfcc830 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xe7/0x320 kernel/umh.c:217 1 lock held by syslogd/3529: #0: ffff8880b913a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 2 locks held by dhcpcd/3839: #0: ffffffff8d212f08 (vlan_ioctl_mutex){+.+.}-{3:3}, at: sock_ioctl+0x273/0x6e0 net/socket.c:1219 #1: ffffffff8d22a808 (rtnl_mutex){+.+.}-{3:3}, at: vlan_ioctl_handler+0xd2/0x610 net/8021q/vlan.c:555 2 locks held by getty/3934: #0: ffff88807f080098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025d62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/4178: #0: ffffffff8c120a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8c120a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 4 locks held by udevd/4185: #0: ffff8880612d6c30 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff88802ae37c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112 #2: ffff888071417cb8 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3c0 fs/kernfs/file.c:113 #3: ffff88807f165220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #3: ffff88807f165220 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17a/0x330 drivers/base/core.c:2408 3 locks held by kworker/1:5/4224: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000320fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88801f621240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480 3 locks held by kworker/1:7/4233: #0: ffff88802a5a6d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000328fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d22a808 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1520 net/ipv6/addrconf.c:4116 3 locks held by kworker/0:8/4534: #0: ffff88802a5a6d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003e1fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d22a808 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1520 net/ipv6/addrconf.c:4116 6 locks held by kworker/1:14/5238: #0: ffff88801b811d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000400fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff888023941220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #2: ffff888023941220 (&dev->mutex){....}-{3:3}, at: hub_event+0x18f/0x4fa0 drivers/usb/core/hub.c:5781 #3: ffff88807f165220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #3: ffff88807f165220 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x107/0x8a0 drivers/usb/core/hub.c:2250 #4: ffff888075bb01a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #4: ffff888075bb01a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline] #4: ffff888075bb01a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb0/0x750 drivers/base/dd.c:1259 #5: ffff888065d88188 (&hdw->big_lock_mutex){+.+.}-{3:3}, at: pvr2_hdw_disconnect+0x69/0x500 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2710 2 locks held by kworker/1:16/5241: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900033ffd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 3 locks held by kworker/u4:12/6304: #0: ffff888016879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900046efd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d22a808 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 3 locks held by syz-executor/14578: #0: ffffffff8d22a808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d22a808 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x974/0xe60 net/core/rtnetlink.c:5647 #1: ffff88807aa113e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_open+0x223/0x420 drivers/net/wireguard/device.c:49 #2: ffffffff8c120a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8c120a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x6b0 kernel/rcu/tree_exp.h:845 1 lock held by syz-executor/14632: #0: ffffffff8d22a808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d22a808 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x974/0xe60 net/core/rtnetlink.c:5647 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.186-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: 14632 Comm: syz-executor Not tainted 5.15.186-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:io_serial_in+0x73/0xb0 drivers/tty/serial/8250/8250_port.c:461 Code: e8 72 9b 31 fd 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 53 14 77 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 44 89 f9 80 e1 07 38 c1 7c aa 4c RSP: 0018:ffffc900031ce4f8 EFLAGS: 00000006 RAX: 1ffffffff2c79105 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc900031ce6d0 R08: 0000000000000004 R09: 0000000000000003 R10: fffff52000639c80 R11: 1ffff92000639c80 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff963c8980 R15: 0000000000000000 FS: 0000555558522500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe2a3798338 CR3: 000000001a39f000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:344 [inline] serial8250_console_write+0x241/0xf80 drivers/tty/serial/8250/8250_port.c:3368 call_console_drivers kernel/printk/printk.c:-1 [inline] console_unlock+0xc86/0x1200 kernel/printk/printk.c:2744 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274 _printk+0xcc/0x110 kernel/printk/printk.c:2299 batadv_check_known_mac_addr+0x272/0x3b0 net/batman-adv/hard-interface.c:522 batadv_hard_if_event+0x4a0/0x17e0 net/batman-adv/hard-interface.c:986 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline] call_netdevice_notifiers net/core/dev.c:2075 [inline] dev_set_mac_address+0x2c4/0x3d0 net/core/dev.c:9114 dev_set_mac_address_user+0x2d/0x50 net/core/dev.c:9128 do_setlink+0x80d/0x3980 net/core/rtnetlink.c:2734 __rtnl_newlink net/core/rtnetlink.c:3450 [inline] rtnl_newlink+0x1419/0x17d0 net/core/rtnetlink.c:3572 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2489 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] netlink_unicast+0x77c/0x920 net/netlink/af_netlink.c:1337 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x423/0x580 net/socket.c:2063 __do_sys_sendto net/socket.c:2075 [inline] __se_sys_sendto net/socket.c:2071 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2071 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: 0033:0x7f239a65d7bc Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b RSP: 002b:00007ffcddf60f80 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f239b3b1620 RCX: 00007f239a65d7bc RDX: 000000000000002c RSI: 00007f239b3b1670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffcddf60fd4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f239b3b1670 R15: 0000000000000000