INFO: task syz.5.622:13353 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.622 state:D stack:25768 pid:13353 tgid:13350 ppid:5977 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 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+0x1c6/0x240 kernel/kthread.c:1564 __alloc_workqueue+0x1470/0x1b70 kernel/workqueue.c:5795 alloc_workqueue_noprof+0xd4/0x210 kernel/workqueue.c:5818 btrfs_alloc_ordered_workqueue+0x1c3/0x290 fs/btrfs/async-thread.c:140 btrfs_init_workqueues+0x3f0/0x6c0 fs/btrfs/disk-io.c:1998 open_ctree+0x141d/0x3d20 fs/btrfs/disk-io.c:3426 btrfs_fill_super fs/btrfs/super.c:987 [inline] btrfs_get_tree_super fs/btrfs/super.c:1951 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2088 [inline] btrfs_get_tree+0xf3c/0x1810 fs/btrfs/super.c:2122 vfs_get_tree+0x92/0x2b0 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3727 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4215 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d9849076a RSP: 002b:00007f0d966ede68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f0d966edef0 RCX: 00007f0d9849076a RDX: 0000200000000000 RSI: 00002000000015c0 RDI: 00007f0d966edeb0 RBP: 0000200000000000 R08: 00007f0d966edef0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000015c0 R13: 00007f0d966edeb0 R14: 000000000000559e R15: 0000200000001600 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5558: #0: ffff88823bf6c0a0 (&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+0x444/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5796: 2 locks held by kworker/u8:12/6193: 1 lock held by syz.5.622/13353: #0: ffff88805f6aa0d0 (&type->s_umount_key#61/1){+.+.}-{4:4}, at: alloc_super+0x1ba/0x9a0 fs/super.c:344 2 locks held by syz.0.816/16131: 2 locks held by syz.6.817/16139: 2 locks held by udevadm/16144: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 16144 Comm: udevadm Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__list_del_entry_valid_or_report+0x2a/0x190 lib/list_debug.c:49 Code: f3 0f 1e fa 41 57 41 56 41 55 41 54 53 48 89 fb 49 bd 00 00 00 00 00 fc ff df 48 83 c7 08 48 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 05 e8 4f 57 96 fd 4c 8b 7b 08 48 89 d8 48 c1 e8 03 42 80 3c 28 RSP: 0018:ffffc90021d3f2e0 EFLAGS: 00000246 RAX: 1ffffd400011a353 RBX: ffffea00008d1a90 RCX: 05900d3332b8c100 RDX: 0000000000000000 RSI: ffffffff8d0405be RDI: ffffea00008d1a98 RBP: ffffea00008d1a80 R08: 0000000000000000 R09: ffffffff8aca4b41 R10: dffffc0000000000 R11: fffffbfff1deed6f R12: 0000000000000000 R13: dffffc0000000000 R14: ffffea00018e1d10 R15: 0000000000000000 FS: 00007f40ce574880(0000) GS:ffff888126cc2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7b8af35000 CR3: 0000000036e7a000 CR4: 00000000003526f0 Call Trace: __list_del_entry_valid include/linux/list.h:132 [inline] __list_del_entry include/linux/list.h:223 [inline] list_del include/linux/list.h:237 [inline] remove_partial mm/slub.c:3360 [inline] get_partial_node+0x10d/0x420 mm/slub.c:3504 get_partial mm/slub.c:3602 [inline] ___slab_alloc+0x9f3/0x13f0 mm/slub.c:4618 __slab_alloc+0xc6/0x1f0 mm/slub.c:4762 __slab_alloc_node mm/slub.c:4838 [inline] slab_alloc_node mm/slub.c:5260 [inline] __do_kmalloc_node mm/slub.c:5633 [inline] __kmalloc_noprof+0x14b/0x7d0 mm/slub.c:5646 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x1c1/0x3b0 security/tomoyo/file.c:771 security_file_open+0xb1/0x270 security/security.c:3183 do_dentry_open+0x378/0x1350 fs/open.c:942 vfs_open+0x3b/0x350 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2ef1/0x3840 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f40ce662407 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:00007ffe8f485920 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f40ce574880 RCX: 00007f40ce662407 RDX: 0000000000080000 RSI: 00007ffe8f485a90 RDI: ffffffffffffff9c RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055f481182ee0 R13: 000055f481182ee0 R14: 0000000000000001 R15: 000055f499372e60