INFO: task udevd:9000 blocked for more than 143 seconds. Not tainted 6.11.0-rc5-syzkaller-00192-gb6ecc6620376 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23872 pid:9000 tgid:9000 ppid:4687 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2557 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 __flush_workqueue+0x7d6/0x1710 kernel/workqueue.c:3968 nbd_disconnect_and_put+0xaa/0x250 drivers/block/nbd.c:2156 nbd_release+0x103/0x130 drivers/block/nbd.c:1650 bdev_release+0x5e3/0x700 blkdev_release+0x15/0x20 block/fops.c:638 __fput+0x24a/0x8a0 fs/file_table.c:422 __do_sys_close fs/open.c:1566 [inline] __se_sys_close fs/open.c:1551 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1551 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f13e55170a8 RSP: 002b:00007ffee2a41d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00007f13e59caae0 RCX: 00007f13e55170a8 RDX: 0000000003938700 RSI: 000000000aba9500 RDI: 0000000000000008 RBP: 0000563cba790fe0 R08: 0000000000000001 R09: 3973a3330efa8bf4 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000002 R13: 0000563cba77b6f0 R14: 0000000000000008 R15: 0000563cba769910 Showing all locks held in the system: 2 locks held by kworker/u8:0/11: 3 locks held by kworker/1:0/25: #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc900001f7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc900001f7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffff88807883a240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2d1/0x4130 drivers/net/netdevsim/fib.c:1489 1 lock held by khungtaskd/30: #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626 2 locks held by getty/4984: #0: ffff8880303ac0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002efe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by kworker/u9:2/5233: #0: ffff88802642c948 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88802642c948 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90003547d00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90003547d00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 3 locks held by kworker/0:5/5313: #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc9000404fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc9000404fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffff888067aa8240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2d1/0x4130 drivers/net/netdevsim/fib.c:1489 3 locks held by kworker/u8:11/5753: #0: ffff88802f6d5948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88802f6d5948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90009df7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90009df7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8fc8ba08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4194 5 locks held by kworker/u8:17/6592: #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90004a57d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90004a57d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8fc7ee50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594 #3: ffffffff8fc8ba08 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xa90 net/core/dev.c:11883 #4: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline] #4: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958 2 locks held by udevd/9000: #0: ffff888025f624c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x184/0x700 block/bdev.c:1080 #1: ffff888026428998 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_disconnect_and_put+0x34/0x250 drivers/block/nbd.c:2148 4 locks held by syz-executor/11097: #0: ffff888012760d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff888012760d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2698 #1: ffff888012760078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5183 #2: ffffffff8fdf74e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1972 [inline] #2: ffffffff8fdf74e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592 #3: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline] #3: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958 3 locks held by syz-executor/11139: #0: ffff88807b578d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff88807b578d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2698 #1: ffff88807b578078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5183 #2: ffffffff8fdf74e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1972 [inline] #2: ffffffff8fdf74e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592 2 locks held by syz-executor/11144: #0: ffffffff8fc7ee50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c6/0x7b0 net/core/net_namespace.c:504 #1: ffffffff8fc8ba08 (rtnl_mutex){+.+.}-{3:3}, at: setup_net+0x83d/0xca0 net/core/net_namespace.c:365 3 locks held by syz.0.1205/11151: #0: ffff88802f974d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff88802f974d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2698 #1: ffff88802f974078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5183 #2: ffffffff8fdf74e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1972 [inline] #2: ffffffff8fdf74e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc5-syzkaller-00192-gb6ecc6620376 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 25 Comm: kworker/1:0 Not tainted 6.11.0-rc5-syzkaller-00192-gb6ecc6620376 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: mld mld_dad_work RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:32 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:123 [inline] RIP: 0010:lock_acquire+0x187/0x550 kernel/locking/lockdep.c:5755 Code: 4c 89 fb 48 c1 eb 03 42 80 3c 2b 00 74 08 4c 89 ff e8 ed 0a 8b 00 48 c7 84 24 80 00 00 00 00 00 00 00 9c 8f 84 24 80 00 00 00 <42> 80 3c 2b 00 74 08 4c 89 ff e8 da 09 8b 00 48 8d 5c 24 60 4c 8b RSP: 0018:ffffc900001f73e0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff9200003ee8c RCX: ffffffff816fcc84 RDX: 0000000000000000 RSI: ffffffff8c608d20 RDI: ffffffff8c608ce0 RBP: ffffc900001f7538 R08: ffffffff90186c2f R09: 1ffffffff2030d85 R10: dffffc0000000000 R11: fffffbfff2030d86 R12: 1ffff9200003ee84 R13: dffffc0000000000 R14: 0000000000000000 R15: ffffc900001f7460 FS: 0000000000000000(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8f1e9ea440 CR3: 000000000e734000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __fs_reclaim_acquire mm/page_alloc.c:3818 [inline] fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3832 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3939 [inline] slab_alloc_node mm/slub.c:4017 [inline] __do_kmalloc_node mm/slub.c:4157 [inline] __kmalloc_node_track_caller_noprof+0xab/0x440 mm/slub.c:4177 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:605 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:674 alloc_skb include/linux/skbuff.h:1320 [inline] alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6526 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2815 sock_alloc_send_skb include/net/sock.h:1778 [inline] mld_newpack+0x1c3/0xa90 net/ipv6/mcast.c:1746 add_grhead net/ipv6/mcast.c:1849 [inline] add_grec+0x1492/0x19a0 net/ipv6/mcast.c:1987 mld_send_initial_cr+0x228/0x4b0 net/ipv6/mcast.c:2233 mld_dad_work+0x44/0x500 net/ipv6/mcast.c:2259 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd10 kernel/workqueue.c:3389 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244