INFO: task udevd:1384 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23464 pid:1384 tgid:1384 ppid:5189 task_flags:0x40054c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1568/0x5290 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 io_schedule+0x7f/0xd0 kernel/sched/core.c:7831 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323 __folio_lock mm/filemap.c:1699 [inline] folio_lock include/linux/pagemap.h:1170 [inline] __filemap_get_folio_mpol+0x13e/0xb00 mm/filemap.c:1954 __filemap_get_folio include/linux/pagemap.h:774 [inline] truncate_inode_pages_range+0x48b/0xe30 mm/truncate.c:413 kill_bdev block/bdev.c:91 [inline] blkdev_flush_mapping+0x109/0x2f0 block/bdev.c:728 blkdev_put_whole block/bdev.c:735 [inline] bdev_release+0x417/0x650 block/bdev.c:1160 blkdev_release+0x15/0x20 block/fops.c:706 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x69b/0x2310 kernel/exit.c:971 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb21f8a7407 RSP: 002b:00007ffe9aa4c8f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: fffffffffffffffc RBX: 00007fb21ff5c880 RCX: 00007fb21f8a7407 RDX: 0000000000000200 RSI: 00007fb21ff5b000 RDI: 0000000000000009 RBP: 000055d589ed6050 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 000055d589ed81f8 R15: 00007fb22008339c Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:5/1112: #0: ffff88801b7c8148 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801b7c8148 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90003adfc40 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90003adfc40 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffff88807e298700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0 drivers/infiniband/core/device.c:1551 #3: ffff8880b873abe0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 #4: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #4: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #4: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline] #4: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: kernfs_root+0x1c/0x230 fs/kernfs/kernfs-internal.h:75 2 locks held by getty/5578: #0: ffff8880372080a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 5 locks held by kworker/u8:21/30861: #0: ffff88801b6ce948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801b6ce948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90003dcfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90003dcfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8fbaffb0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248 #4: ffff8880287ee500 (&p->pi_lock){-.-.}-{2:2}, at: kernfs_find_and_get_ns+0x34/0xe0 fs/kernfs/dir.c:938 1 lock held by udevd/1384: #0: ffff888026c20358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1144 3 locks held by kworker/u8:23/4883: #0: ffff88813fe44148 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe44148 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc9000bbe7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000bbe7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 3 locks held by kworker/1:0/9085: #0: ffff88813fe03548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe03548 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc9000cc07c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000cc07c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by syz.1.10922/13196: #0: ffff8880418fc6f0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404 #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826 2 locks held by syz.3.10924/13200: #0: ffffffff8fb9fbc8 (br_ioctl_mutex){+.+.}-{4:4}, at: br_ioctl_call net/socket.c:1225 [inline] #0: ffffffff8fb9fbc8 (br_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x4fa/0x7f0 net/socket.c:1329 #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: br_ioctl_stub+0x1a8/0xd60 net/bridge/br_ioctl.c:418 2 locks held by syz.3.10924/13206: #0: ffffffff901295d8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff901295d8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff901295d8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz.0.10927/13214: #0: ffffffff90127cd0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff90127cd0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff90127cd0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz.0.10927/13217: #0: ffffffff8fc2c430 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:18070 2 locks held by syz.2.10929/13219: #0: ffff88807e0be6f0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404 #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826 1 lock held by syz.4.10930/13226: #0: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 1 lock held by syz.4.10930/13227: #0: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:6964 1 lock held by syz.4.10930/13228: #0: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: dev_ethtool+0x1e1/0x1ae0 net/ethtool/ioctl.c:3571 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30861 Comm: kworker/u8:21 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: netns cleanup_net RIP: 0010:div_s64_rem include/linux/math64.h:43 [inline] RIP: 0010:div_s64 include/linux/math64.h:145 [inline] RIP: 0010:avg_vruntime kernel/sched/fair.c:708 [inline] RIP: 0010:update_zero_vruntime kernel/sched/fair.c:782 [inline] RIP: 0010:__enqueue_entity+0x226/0x7b0 kernel/sched/fair.c:859 Code: ff 48 89 e9 48 c1 f9 3f 48 21 c1 48 29 cd 49 63 cf 48 89 e8 48 09 c8 48 c1 e8 20 4c 8b 74 24 18 74 14 48 89 e8 48 99 48 f7 f9 <48> 89 c5 eb 10 4c 8b 74 24 18 eb 09 89 e8 31 d2 41 f7 f7 89 c5 4c RSP: 0018:ffffc90000007ac0 EFLAGS: 00000802 RAX: ffffffffffc9725b RBX: fffffffdd0cb1000 RCX: 0000000000000800 RDX: fffffffffffff801 RSI: ffff88807659bd00 RDI: ffff8880b863ac68 RBP: fffffffe4b92d001 R08: ffffffff90109077 R09: 1ffffffff202120e R10: dffffc0000000000 R11: fffffbfff202120f R12: ffff88807659bd00 R13: 0000000000000400 R14: ffff8880b863ac60 R15: 0000000000000800 FS: 0000000000000000(0000) GS:ffff8881254b0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c26bc1e CR3: 000000007591c000 CR4: 00000000003526f0 Call Trace: enqueue_entity kernel/sched/fair.c:5257 [inline] enqueue_task_fair+0xbb2/0x2b60 kernel/sched/fair.c:6926 enqueue_task+0x75/0x410 kernel/sched/core.c:2107 activate_task kernel/sched/core.c:2147 [inline] ttwu_do_activate+0x1cc/0x660 kernel/sched/core.c:3667 ttwu_queue kernel/sched/core.c:3918 [inline] try_to_wake_up+0x724/0x1390 kernel/sched/core.c:4242 hrtimer_wakeup+0x4e/0x60 kernel/time/hrtimer.c:2021 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x529/0xc30 kernel/time/hrtimer.c:1849 hrtimer_interrupt+0x42b/0x1010 kernel/time/hrtimer.c:1911 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3d0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478 Code: 0f 84 44 ff ff ff e8 52 fb 20 00 fb eb 44 e8 4a fb 20 00 e8 05 13 fb 09 4d 85 f6 74 94 e8 3b fb 20 00 fb 48 c7 c7 c0 04 75 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 3b 1b RSP: 0018:ffffc90003dcf220 EFLAGS: 00000293 RAX: ffffffff81a33f95 RBX: ffffffff81a33e0f RCX: ffff88802ac40000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e7504c0 RBP: ffffc90003dcf2d0 R08: ffffffff90109077 R09: 1ffffffff202120e R10: dffffc0000000000 R11: fffffbfff202120f R12: 0000000000000000 R13: 0000000000000042 R14: 0000000000000200 R15: 1ffff920007b9e48 _printk+0xdd/0x130 kernel/printk/printk.c:2504 netdev_info+0x11e/0x180 net/core/dev.c:12971 __bond_release_one+0x543/0x1150 drivers/net/bonding/bond_main.c:2423 bond_uninit+0x129/0x2d0 drivers/net/bonding/bond_main.c:5995 unregister_netdevice_many_notify+0x1d16/0x2370 net/core/dev.c:12417 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x3d3/0x940 net/core/net_namespace.c:248 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245