INFO: task udevd:5828 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:21984 pid:5828 tgid:5828 ppid:5195 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 io_schedule+0x7f/0xd0 kernel/sched/core.c:7835 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323 folio_put_wait_locked mm/filemap.c:1492 [inline] do_read_cache_folio+0x1ad/0x590 mm/filemap.c:4083 read_mapping_folio include/linux/pagemap.h:1028 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:723 adfspart_check_POWERTEC+0x92/0xef0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:142 [inline] blk_add_partitions block/partitions/core.c:590 [inline] bdev_disk_changed+0x7ba/0x1550 block/partitions/core.c:694 blkdev_get_whole+0x380/0x510 block/bdev.c:764 bdev_open+0x31e/0xd30 block/bdev.c:973 blkdev_open+0x470/0x610 block/fops.c:697 do_dentry_open+0x785/0x14e0 fs/open.c:949 vfs_open+0x3b/0x340 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4830 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa5a7ca7407 RSP: 002b:00007ffc1407e9b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fa5a7c1d880 RCX: 00007fa5a7ca7407 RDX: 00000000000a0800 RSI: 000055e127b0c320 RDI: ffffffffffffff9c RBP: 000055e127b0b910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055e127b326d0 R13: 000055e127b19190 R14: 0000000000000000 R15: 000055e127b326d0 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u9:0/52: #0: ffff888026742148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888026742148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90000bc7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90000bc7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 3 locks held by kworker/u8:8/1016: #0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000533fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000533fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8fbcf1c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 6 locks held by kworker/u8:9/1154: #0: ffff88801b6de948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801b6de948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc900056ffc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc900056ffc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8fbc0a50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffffffff8fbcf1c8 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x200 drivers/net/wireguard/device.c:419 #4: ffff88804b0d5568 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_netns_pre_exit+0xb0/0x200 drivers/net/wireguard/device.c:424 #5: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #5: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 2 locks held by getty/5583: #0: ffff8880322050a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5828: #0: ffff888026726358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961 1 lock held by syz-executor/18364: #0: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 26527 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:queued_spin_trylock include/asm-generic/qspinlock.h:94 [inline] RIP: 0010:do_raw_spin_trylock+0x8a/0x190 kernel/locking/spinlock_debug.c:123 Code: 43 c6 44 3c 04 04 be 04 00 00 00 e8 a0 c9 8d 00 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 cf 00 00 00 8b 03 89 44 24 20 <85> c0 0f 85 b7 00 00 00 4c 8d 74 24 20 48 89 df be 04 00 00 00 e8 RSP: 0018:ffffc90002f67a60 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880b8740f00 RCX: ffffffff81a22fe0 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880b8740f00 RBP: ffffc90002f67af0 R08: ffff8880b8740f03 R09: 1ffff110170e81e0 R10: dffffc0000000000 R11: ffffed10170e81e1 R12: 1ffff920005ecf4c R13: ffff88823fff8300 R14: ffff8880b8740f00 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff88812555a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562255f4dee8 CR3: 000000000e54c000 CR4: 00000000003526f0 Call Trace: __raw_spin_trylock include/linux/spinlock_api_smp.h:90 [inline] _raw_spin_trylock+0x21/0x80 kernel/locking/spinlock.c:138 spin_trylock include/linux/spinlock.h:353 [inline] __free_frozen_pages+0x6cf/0xdb0 mm/page_alloc.c:3003 vfree+0x25a/0x400 mm/vmalloc.c:3479 kcov_put kernel/kcov.c:442 [inline] kcov_close+0x28/0x50 kernel/kcov.c:543 __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+0x70f/0x23c0 kernel/exit.c:976 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 __do_sys_exit_group kernel/exit.c:1129 [inline] __se_sys_exit_group kernel/exit.c:1127 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1127 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a8399c819 Code: Unable to access opcode bytes at 0x7f4a8399c7ef. RSP: 002b:00007ffe63f350e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f4a83a33bd9 RCX: 00007f4a8399c819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043 RBP: 00007f4a83a33beb R08: 0000000000000000 R09: 00000000000927c0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 00000000000927c0 R14: 00000000000964bf R15: 00007ffe63f35290