INFO: task syz.3.259:9131 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.259 state:D stack:25464 pid:9131 tgid:9130 ppid:5812 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x9a/0x270 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+0x2bf/0x5d0 kernel/sched/completion.c:153 kthread_flush_worker+0x10e/0x160 kernel/kthread.c:1559 __alloc_workqueue+0x1485/0x1b80 kernel/workqueue.c:5797 alloc_workqueue_noprof+0xd4/0x210 kernel/workqueue.c:5820 btrfs_alloc_workqueue+0x1ec/0x2d0 fs/btrfs/async-thread.c:112 btrfs_init_workqueues+0x2ab/0x680 fs/btrfs/disk-io.c:1980 open_ctree+0x141d/0x3d20 fs/btrfs/disk-io.c:3410 btrfs_fill_super fs/btrfs/super.c:983 [inline] btrfs_get_tree_super fs/btrfs/super.c:1946 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2089 [inline] btrfs_get_tree+0x1061/0x1920 fs/btrfs/super.c:2123 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3712 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8419bc0eea RSP: 002b:00007f8417e25e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f8417e25ef0 RCX: 00007f8419bc0eea RDX: 00002000000055c0 RSI: 0000200000000000 RDI: 00007f8417e25eb0 RBP: 00002000000055c0 R08: 00007f8417e25ef0 R09: 000000000300000a R10: 000000000300000a R11: 0000000000000246 R12: 0000200000000000 R13: 00007f8417e25eb0 R14: 00000000000055a3 R15: 0000200000000080 Showing all locks held in the system: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:13/3452: 1 lock held by udevd/5171: 2 locks held by getty/5562: #0: ffff8880306550a0 (&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+0x44f/0x1460 drivers/tty/n_tty.c:2211 4 locks held by udevd/6608: 1 lock held by syz.3.259/9131: #0: ffff888032f500d0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344 2 locks held by syz.1.445/11516: 2 locks held by syz.5.446/11518: #0: ffff888038b140d0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344 #1: ffffffff8d456998 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5215 [inline] #1: ffffffff8d456998 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa07/0x1b80 kernel/workqueue.c:5768 2 locks held by syz.0.447/11529: #0: ffff888010ece0d0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344 #1: ffffffff8d456998 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5215 [inline] #1: ffffffff8d456998 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa07/0x1b80 kernel/workqueue.c:5768 1 lock held by udevadm/11551: ============================================= 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 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [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+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6608 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 0b 57 5b f6 cc RSP: 0018:ffffc9000e00f978 EFLAGS: 00000293 RAX: ffffffff843dcfdc RBX: ffffc9000e00fa00 RCX: ffff88801bb35ac0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000004 R08: ffffc9000e00fb8f R09: 0000000000000000 R10: ffffc9000e00fb80 R11: fffff52001c01f72 R12: ffffc9000e00fc80 R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007f0393479880(0000) GS:ffff888126e01000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2ebadcc000 CR3: 0000000033730000 CR4: 00000000003526f0 Call Trace: tomoyo_init_request_info+0x1c/0x340 security/tomoyo/util.c:1021 tomoyo_path_perm+0x182/0x4b0 security/tomoyo/file.c:815 security_inode_getattr+0x12f/0x330 security/security.c:1869 vfs_getattr fs/stat.c:259 [inline] vfs_statx_path fs/stat.c:299 [inline] vfs_statx+0x18e/0x550 fs/stat.c:356 vfs_fstatat+0x118/0x170 fs/stat.c:375 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f03935d1b0a Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7 RSP: 002b:00007ffd5f798e18 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 00007f03935d1b0a RDX: 00007ffd5f798e20 RSI: 00007ffd5f798ef0 RDI: 00000000ffffff9c RBP: 00007ffd5f799f30 R08: 0000000000000064 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd5f799f40 R13: 0000000000000000 R14: 0000000000000008 R15: 000055ea2fe93830