INFO: task syz.6.2360:24047 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.2360 stat[ 1496.978493][ T38] task:syz.6.2360 state:D stack:25664 pid:24047 tgid:24045 ppid:21258 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14fb/0x52c0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153 kthread_flush_worker+0x138/0x1a0 kernel/kthread.c:1610 __alloc_workqueue+0xfed/0x1e90 kernel/workqueue.c:5860 alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:5883 btrfs_alloc_workqueue+0x1ec/0x2d0 fs/btrfs/async-thread.c:112 btrfs_init_workqueues+0xb0/0x680 fs/btrfs/disk-io.c:1920 open_ctree+0x1598/0x4220 fs/btrfs/disk-io.c:3448 btrfs_fill_super fs/btrfs/super.c:981 [inline] btrfs_get_tree_super fs/btrfs/super.c:1944 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline] btrfs_get_tree+0x1061/0x1930 fs/btrfs/super.c:2121 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 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: 0033:0x7f702d9cd8ca RSP: 002b:00007f702bc25e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f702bc25ee0 RCX: 00007f702d9cd8ca RDX: 0000200000000000 RSI: 00002000000015c0 RDI: 00007f702bc25ea0 RBP: 0000200000000000 R08: 00007f702bc25ee0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000015c0 R13: 00007f702bc25ea0 R14: 000000000000559e R15: 0000200000000440 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:4/68: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc9000153fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000153fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 2 locks held by udevd/5159: 2 locks held by getty/5549: #0: ffff8880284680a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 5 locks held by kworker/u8:13/7966: #0: ffff88801aed9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801aed9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc9000dc67c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000dc67c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8f14afc0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x200 drivers/net/wireguard/device.c:419 #4: ffff888086dd97b8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_netns_pre_exit+0xb0/0x200 drivers/net/wireguard/device.c:424 1 lock held by udevd/20442: 1 lock held by syz.6.2360/24047: #0: ffff88803d47a0d0 (&type->s_umount_key#67/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 1 lock held by syz-executor/24828: 2 locks held by syz.4.2583/26157: 1 lock held by syz.7.2585/26165: #0: ffff88803ddce0d0 (&type->s_umount_key#56/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 1 lock held by udevadm/26204: 2 locks held by rm/26206: 1 lock held by syz.2.2588/26207: 1 lock held by syz.1.2587/26209: 2 locks held by syz.1.2587/26211: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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: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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 26204 Comm: udevadm Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:unwind_next_frame+0x1834/0x23c0 arch/x86/kernel/unwind_orc.c:663 Code: 81 9f dd 10 01 4c 89 f7 e8 b9 0b 00 00 e9 f8 01 00 00 48 8b 54 24 08 48 8d 5a 02 48 83 c2 03 48 89 d8 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 49 0a 00 00 48 89 d0 48 c1 e8 03 0f b6 04 28 84 c0 48 RSP: 0018:ffffc9000b6b7058 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: ffffffff9005d02c RCX: 0000000000000000 RDX: ffffffff9005d02d RSI: 0000000000000001 RDI: ffffc9000b6b7188 RBP: dffffc0000000000 R08: ffffc9000b6b7187 R09: 0000000000000000 R10: ffffc9000b6b7178 R11: fffff520016d6e31 R12: ffffc9000b6b7178 R13: 1ffff920016d6e27 R14: ffffc9000b6b7128 R15: 1ffffffff200ba05 FS: 00007fad1eb2b880(0000) GS:ffff888126443000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055bb81f795f8 CR3: 000000003a32c000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5219 [inline] __kmalloc_noprof+0x3e7/0x7b0 mm/slub.c:5231 kmalloc_noprof include/linux/slab.h:966 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x229/0x470 security/tomoyo/file.c:776 security_file_open+0xa9/0x240 security/security.c:2636 do_dentry_open+0x4c0/0x13e0 fs/open.c:926 vfs_open+0x3b/0x350 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x2e43/0x38a0 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: 0033:0x7fad1ec19407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffd8ad9df70 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fad1eb2b880 RCX: 00007fad1ec19407 RDX: 0000000000080000 RSI: 00007ffd8ad9e0f0 RDI: ffffffffffffff9c RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055bb6cc57ee0 R13: 000055bb6cc57ee0 R14: 0000000000000001 R15: 000055bb81f76e60