INFO: task udevd:4179 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:25264 pid: 4179 ppid: 3561 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 wait_on_page_bit_common+0x83b/0xe50 mm/filemap.c:1356 wait_on_page_bit mm/filemap.c:1417 [inline] wait_on_page_locked include/linux/pagemap.h:688 [inline] wait_on_page_read mm/filemap.c:3437 [inline] do_read_cache_page+0xb05/0x1030 mm/filemap.c:3480 read_mapping_page include/linux/pagemap.h:515 [inline] read_part_sector+0xd4/0x4f0 block/partitions/core.c:726 adfspart_check_ICS+0xc3/0xe40 block/partitions/acorn.c:360 check_partition block/partitions/core.c:148 [inline] blk_add_partitions block/partitions/core.c:611 [inline] bdev_disk_changed+0x933/0x16c0 block/partitions/core.c:697 blkdev_get_whole+0x2f9/0x390 block/bdev.c:682 blkdev_get_by_dev+0x2d0/0xa60 block/bdev.c:827 blkdev_open+0x12d/0x2c0 block/fops.c:466 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x26f5/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 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: 0033:0x7ffa200b1407 RSP: 002b:00007ffeff296b70 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffa1ffc3880 RCX: 00007ffa200b1407 RDX: 0000000000080000 RSI: 0000558016e2ba30 RDI: ffffffffffffff9c RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055801578495f R13: 0000558015795660 R14: 0000000000000000 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 3 locks held by kworker/u4:2/154: #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90002057d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d4308d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589 2 locks held by kworker/1:2/1111: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90004ba7d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 1 lock held by klogd/3550: #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 2 locks held by getty/3947: #0: ffff88802c88d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 1 lock held by udevd/4179: #0: ffff888020952918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 3 locks held by kworker/1:4/4231: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900031dfd00 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8c323430 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4c0 kernel/rcu/tree.c:4043 3 locks held by kworker/1:9/4614: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90003bf7d00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 3 locks held by kworker/1:18/4623: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000419fd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 3 locks held by syz-executor/7711: #0: ffff88801f9a0ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1030 net/bluetooth/hci_core.c:1737 #1: ffff88801f9a0078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x3f4/0x1030 net/bluetooth/hci_core.c:1782 #2: ffffffff8d582668 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1517 [inline] #2: ffffffff8d582668 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622 3 locks held by syz.6.1053/8171: #0: ffff888079db4ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1030 net/bluetooth/hci_core.c:1737 #1: ffff888079db4078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x3f4/0x1030 net/bluetooth/hci_core.c:1782 #2: ffffffff8d582668 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1517 [inline] #2: ffffffff8d582668 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622 1 lock held by syz.1.1068/8245: #0: ffffffff9669b798 (nfnl_subsys_ipset){+.+.}-{3:3}, at: call_ad+0x260/0xa00 net/netfilter/ipset/ip_set_core.c:1748 3 locks held by syz-executor/8277: #0: ffff888025ac4ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1030 net/bluetooth/hci_core.c:1737 #1: ffff888025ac4078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x3f4/0x1030 net/bluetooth/hci_core.c:1782 #2: ffffffff8d582668 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1517 [inline] #2: ffffffff8d582668 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622 3 locks held by rm/8303: ============================================= 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 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7224 Comm: kworker/0:15 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events pwq_unbound_release_workfn RIP: 0010:remove_class_from_lock_chain kernel/locking/lockdep.c:5913 [inline] RIP: 0010:remove_class_from_lock_chains kernel/locking/lockdep.c:5952 [inline] RIP: 0010:zap_class+0x2e5/0x890 kernel/locking/lockdep.c:5997 Code: 3f 4d 85 ff 0f 94 c0 49 83 c7 f8 0f 94 c1 08 c1 75 b5 4d 89 fd 49 c1 ed 03 43 0f b6 44 35 00 84 c0 0f 85 4d 02 00 00 45 8b 27 <41> f6 c4 fc 0f 84 0b 02 00 00 41 c1 ec 08 44 89 e5 01 ed 49 81 fc RSP: 0018:ffffc90003c77ac0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000884 RCX: 0000000000000c00 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff8f11a8b4 RBP: 0000000000001936 R08: ffffffff90183057 R09: 1ffffffff203060a R10: dffffc0000000000 R11: fffffbfff203060b R12: 0000000002b14828 R13: 1ffffffff2061888 R14: dffffc0000000000 R15: ffffffff9030c440 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efc29966eb8 CR3: 000000007f01a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lockdep_free_key_range kernel/locking/lockdep.c:6126 [inline] lockdep_unregister_key+0x341/0x520 kernel/locking/lockdep.c:6328 wq_unregister_lockdep kernel/workqueue.c:3518 [inline] pwq_unbound_release_workfn+0x262/0x2b0 kernel/workqueue.c:3756 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun