INFO: task syz.7.1976:22446 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.1976 state:D stack:25536 pid:22446 tgid:22445 ppid:16202 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_ordered_workqueue+0x1c3/0x290 fs/btrfs/async-thread.c:140 btrfs_init_workqueues+0x396/0x680 fs/btrfs/disk-io.c:1948 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:3763 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3839 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4338 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: 0033:0x7fb637c1da0a RSP: 002b:00007fb635e6de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fb635e6dee0 RCX: 00007fb637c1da0a RDX: 0000200000005100 RSI: 0000200000000040 RDI: 00007fb635e6dea0 RBP: 0000200000005100 R08: 00007fb635e6dee0 R09: 0000000000800810 R10: 0000000000800810 R11: 0000000000000246 R12: 0000200000000040 R13: 00007fb635e6dea0 R14: 000000000000510a R15: 0000200000000140 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 6 locks held by kworker/u8:5/95: 2 locks held by kworker/u8:11/3597: 1 lock held by udevd/5161: #0: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x9e/0x5e0 fs/kernfs/dir.c:1185 2 locks held by getty/5556: #0: ffff888036dd80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/16376: 2 locks held by udevd/17034: 1 lock held by syz-executor/17108: 1 lock held by syz.7.1976/22446: #0: ffff8880294540d0 (&type->s_umount_key#53/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 1 lock held by syz-executor/23812: #0: ffffffff8da0c0a8 (tasklist_lock){++++}-{3:3}, at: read_lock include/linux/rwlock_rt.h:38 [inline] #0: ffffffff8da0c0a8 (tasklist_lock){++++}-{3:3}, at: __do_wait+0xe1/0x740 kernel/exit.c:1672 7 locks held by syz.9.2227/24822: 1 lock held by syz.5.2230/24828: 2 locks held by syz.3.2232/24834: 3 locks held by syz-executor/24835: 1 lock held by dhcpcd-run-hook/24858: #0: ffffffff8da0c0a8 (tasklist_lock){++++}-{3:3}, at: read_lock include/linux/rwlock_rt.h:38 [inline] #0: ffffffff8da0c0a8 (tasklist_lock){++++}-{3:3}, at: __do_wait+0xe1/0x740 kernel/exit.c:1672 1 lock held by syz.2.2233/24861: ============================================= 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: 17034 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x80 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d a4 9c bb 0b 48 89 de 5b e9 53 90 5a 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d c8 ac 89 10 65 8b 35 e9 ac 89 RSP: 0018:ffffc900046475b8 EFLAGS: 00000246 RAX: 0000000000000004 RBX: 0000000000000001 RCX: 0000000000000005 RDX: ffffffff8b1af518 RSI: ffffffff8f512f50 RDI: 0000000000000001 RBP: ffffc900046477b0 R08: ffff8880328a1e40 R09: 0000000000000004 R10: 0000000000000100 R11: 0000000000000003 R12: ffff88802b67ec00 R13: ffffffffffffffff R14: ffff88802b67ec40 R15: 0000000000000007 FS: 00007f3b57229880(0000) GS:ffff888126440000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f908f63dc00 CR3: 00000000332fa000 CR4: 00000000003526f0 Call Trace: ma_slots lib/maple_tree.c:708 [inline] mas_get_slot lib/maple_tree.c:6632 [inline] mas_validate_gaps lib/maple_tree.c:6900 [inline] mt_validate+0x23d3/0x4340 lib/maple_tree.c:7176 validate_mm+0xd4/0x4c0 mm/vma.c:649 vms_complete_munmap_vmas+0x9b1/0xc60 mm/vma.c:1345 do_vmi_align_munmap+0x3bd/0x4d0 mm/vma.c:1585 do_vmi_munmap+0x252/0x2d0 mm/vma.c:1633 __vm_munmap+0x22c/0x3d0 mm/vma.c:3254 __do_sys_munmap mm/mmap.c:1078 [inline] __se_sys_munmap mm/mmap.c:1075 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1075 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: 0033:0x7f3b5738e097 Code: 73 01 c3 48 8b 0d 61 2d 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 31 2d 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffcb1648458 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 00005595054f3db0 RCX: 00007f3b5738e097 RDX: 00005595054f3df8 RSI: 0000000000000200 RDI: 00007f3b568bb000 RBP: 0000000000000010 R08: 00005595054e2a40 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000246 R12: 00005595054eefe0 R13: 00007f3b57a6d39c R14: 0000000000002000 R15: 0000000000000009