INFO: task udevd:4447 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:25312 pid: 4447 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 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+0x815/0xe00 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:731 adfspart_check_ICS+0xbf/0xe00 block/partitions/acorn.c:360 check_partition block/partitions/core.c:148 [inline] blk_add_partitions block/partitions/core.c:616 [inline] bdev_disk_changed+0x917/0x16b0 block/partitions/core.c:702 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:3608 [inline] path_openat+0x2682/0x2f30 fs/namei.c:3742 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 do_sys_openat2+0x142/0x4a0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 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: 0033:0x7feb9f18e407 RSP: 002b:00007ffceab27690 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007feb9f0a0880 RCX: 00007feb9f18e407 RDX: 00000000000a0800 RSI: 000055d4cae1c120 RDI: ffffffffffffff9c RBP: 000055d4cae06910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055d4cae1aba0 R13: 000055d4cae1e410 R14: 0000000000000000 R15: 000055d4cae1aba0 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3944: #0: ffff88802c3f3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 4 locks held by udevd/4373: #0: ffff88806975c540 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff88805f818c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112 #2: ffff8880230f6bd0 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3c0 fs/kernfs/file.c:113 #3: ffff8880254bc220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #3: ffff8880254bc220 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17a/0x330 drivers/base/core.c:2408 1 lock held by udevd/4447: #0: ffff888020903d18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 5 locks held by kworker/0:12/4596: #0: ffff88801ba88d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900040cfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff8880242d7220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #2: ffff8880242d7220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x5560 drivers/usb/core/hub.c:5827 #3: ffff8880254bc220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #3: ffff8880254bc220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:954 #4: ffff88801bb51278 (&(&priv->bus_notifier)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x5e/0x1b0 kernel/notifier.c:317 2 locks held by kworker/0:13/4597: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900048b7d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 5 locks held by kworker/u4:11/4648: #0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900012ffd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d22c3d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589 #3: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0xbf/0x490 net/ipv6/ip6_gre.c:1647 #4: ffffffff8c1210e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #4: ffffffff8c1210e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x6b0 kernel/rcu/tree_exp.h:845 3 locks held by kworker/1:17/5184: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003acfd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c1210e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8c1210e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x6b0 kernel/rcu/tree_exp.h:845 2 locks held by syz-executor/9067: #0: ffff8880208d1118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff88802089c468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 1 lock held by syz.3.925/10448: #0: ffff888020903d18 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1ab/0x320 block/bdev.c:1053 2 locks held by syz.8.1015/11102: 3 locks held by syz.2.1032/11172: #0: ffff88805f7e8ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1030 net/bluetooth/hci_core.c:1737 #1: ffff88805f7e8078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x3f4/0x1030 net/bluetooth/hci_core.c:1782 #2: ffffffff8d37e4e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1517 [inline] #2: ffffffff8d37e4e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622 3 locks held by syz.4.1033/11181: #0: ffff88804f8d0ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1030 net/bluetooth/hci_core.c:1737 #1: ffff88804f8d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x3f4/0x1030 net/bluetooth/hci_core.c:1782 #2: ffffffff8d37e4e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1517 [inline] #2: ffffffff8d37e4e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622 2 locks held by dhcpcd-run-hook/11230: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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: 6532 Comm: kworker/u4:16 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker RIP: 0010:visit_lock_entry kernel/locking/lockdep.c:1481 [inline] RIP: 0010:__bfs kernel/locking/lockdep.c:1761 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1805 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2745 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3057 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3172 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3788 [inline] RIP: 0010:__lock_acquire+0x3404/0x7c60 kernel/locking/lockdep.c:5012 Code: 39 f7 48 ba 00 00 00 00 00 fc ff df 75 0d e9 8a fb ff ff 4d 8b 3f 4d 39 f7 74 45 49 8d 7f 30 48 89 f8 48 c1 e8 03 80 3c 10 00 <74> 0f e8 45 02 60 00 48 ba 00 00 00 00 00 fc ff df 49 89 5f 30 4c RSP: 0018:ffffc9000314f4c0 EFLAGS: 00000046 RAX: 1ffffffff2531429 RBX: ffffffff9298b0d8 RCX: dffffc0000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff9298a148 RBP: ffffc9000314f710 R08: dffffc0000000000 R09: ffffc9000314f660 R10: fffff52000629ed3 R11: 1ffff92000629ecc R12: ffffffff92006ab0 R13: 00000000000003fc R14: ffffffff8f9b1630 R15: ffffffff9298a118 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f29f304de9c CR3: 000000000be8e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 local_lock_acquire+0x1d/0x70 include/linux/local_lock_internal.h:29 put_cpu_partial+0x6b/0x190 mm/slub.c:2561 get_partial_node+0x1b7/0x250 mm/slub.c:2149 get_partial mm/slub.c:2237 [inline] ___slab_alloc+0x5b9/0xdf0 mm/slub.c:3008 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node_track_caller+0x1fc/0x3a0 mm/slub.c:4963 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x22c/0x750 net/core/skbuff.c:427 alloc_skb include/linux/skbuff.h:1162 [inline] wg_socket_send_buffer_to_peer+0x34/0x170 drivers/net/wireguard/socket.c:192 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x1d8/0x310 drivers/net/wireguard/send.c:51 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287