====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz-executor/5806 is trying to acquire lock: ffff88807ab04868 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x163/0x1d40 fs/pipe.c:458 but task is already holding lock: ffff888033264948 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_write fs/autofs/waitq.c:55 [inline] ffff888033264948 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_notify_daemon+0x4f8/0xd90 fs/autofs/waitq.c:164 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&sbi->pipe_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776 autofs_write fs/autofs/waitq.c:55 [inline] autofs_notify_daemon+0x4f8/0xd90 fs/autofs/waitq.c:164 autofs_wait+0x10fd/0x1b50 fs/autofs/waitq.c:426 autofs_mount_wait+0x132/0x3b0 fs/autofs/root.c:255 autofs_d_automount+0x490/0x950 fs/autofs/root.c:409 follow_automount fs/namei.c:1560 [inline] __traverse_mounts+0x1b9/0x8a0 fs/namei.c:1613 traverse_mounts fs/namei.c:1642 [inline] handle_mounts fs/namei.c:1744 [inline] step_into_slowpath+0xb7e/0xf90 fs/namei.c:2101 step_into fs/namei.c:2149 [inline] walk_component fs/namei.c:2285 [inline] lookup_last fs/namei.c:2786 [inline] path_lookupat+0x58b/0xc40 fs/namei.c:2810 filename_lookup+0x202/0x590 fs/namei.c:2839 kern_path+0x37/0x50 fs/namei.c:3046 lookup_bdev+0xd8/0x280 block/bdev.c:1221 resume_store+0x1d6/0x460 kernel/power/hibernate.c:1306 kobj_attr_store+0x58/0x80 lib/kobject.c:840 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352 aio_write+0x3ba/0x920 fs/aio.c:1633 __io_submit_one fs/aio.c:2005 [inline] io_submit_one+0x1142/0x1fb0 fs/aio.c:2052 __do_sys_io_submit fs/aio.c:2111 [inline] __se_sys_io_submit fs/aio.c:2081 [inline] __x64_sys_io_submit+0x1b1/0x3a0 fs/aio.c:2081 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&of->mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776 kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343 iter_file_splice_write+0x830/0x10a0 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] do_splice+0x109c/0x1fd0 fs/splice.c:1349 __do_splice+0x33b/0x370 fs/splice.c:1431 __do_sys_splice fs/splice.c:1634 [inline] __se_sys_splice fs/splice.c:1616 [inline] __x64_sys_splice+0x187/0x250 fs/splice.c:1616 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&pipe->mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776 anon_pipe_write+0x163/0x1d40 fs/pipe.c:458 __kernel_write_iter+0x6b2/0x920 fs/read_write.c:621 __kernel_write+0xf6/0x140 fs/read_write.c:641 autofs_write fs/autofs/waitq.c:57 [inline] autofs_notify_daemon+0x50d/0xd90 fs/autofs/waitq.c:164 autofs_wait+0x10fd/0x1b50 fs/autofs/waitq.c:426 autofs_mount_wait+0x132/0x3b0 fs/autofs/root.c:255 autofs_d_automount+0x490/0x950 fs/autofs/root.c:409 follow_automount fs/namei.c:1560 [inline] __traverse_mounts+0x1b9/0x8a0 fs/namei.c:1613 traverse_mounts fs/namei.c:1642 [inline] handle_mounts fs/namei.c:1744 [inline] step_into_slowpath+0xb7e/0xf90 fs/namei.c:2101 step_into fs/namei.c:2149 [inline] open_last_lookups fs/namei.c:4624 [inline] path_openat+0xf95/0x31a0 fs/namei.c:4833 do_file_open+0x20e/0x430 fs/namei.c:4865 do_sys_openat2+0x10d/0x1e0 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+0x12d/0x210 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &pipe->mutex --> &of->mutex --> &sbi->pipe_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->pipe_mutex); lock(&of->mutex); lock(&sbi->pipe_mutex); lock(&pipe->mutex); *** DEADLOCK *** 1 lock held by syz-executor/5806: #0: ffff888033264948 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_write fs/autofs/waitq.c:55 [inline] #0: ffff888033264948 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_notify_daemon+0x4f8/0xd90 fs/autofs/waitq.c:164 stack backtrace: CPU: 0 UID: 0 PID: 5806 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776 anon_pipe_write+0x163/0x1d40 fs/pipe.c:458 __kernel_write_iter+0x6b2/0x920 fs/read_write.c:621 __kernel_write+0xf6/0x140 fs/read_write.c:641 autofs_write fs/autofs/waitq.c:57 [inline] autofs_notify_daemon+0x50d/0xd90 fs/autofs/waitq.c:164 autofs_wait+0x10fd/0x1b50 fs/autofs/waitq.c:426 autofs_mount_wait+0x132/0x3b0 fs/autofs/root.c:255 autofs_d_automount+0x490/0x950 fs/autofs/root.c:409 follow_automount fs/namei.c:1560 [inline] __traverse_mounts+0x1b9/0x8a0 fs/namei.c:1613 traverse_mounts fs/namei.c:1642 [inline] handle_mounts fs/namei.c:1744 [inline] step_into_slowpath+0xb7e/0xf90 fs/namei.c:2101 step_into fs/namei.c:2149 [inline] open_last_lookups fs/namei.c:4624 [inline] path_openat+0xf95/0x31a0 fs/namei.c:4833 do_file_open+0x20e/0x430 fs/namei.c:4865 do_sys_openat2+0x10d/0x1e0 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+0x12d/0x210 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f757039bb3c Code: 4c 89 54 24 18 41 89 f2 41 83 e2 40 75 40 89 f0 f7 d0 a9 00 00 41 00 74 35 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 77 44 48 8b 54 24 18 64 48 2b 14 25 28 00 00 00 RSP: 002b:00007ffe92381580 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f7570432048 RCX: 00007f757039bb3c RDX: 0000000000090800 RSI: 00007ffe92382790 RDI: 00000000ffffff9c RBP: 00007ffe92382790 R08: 00007ffe92383790 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffe92382790 R13: 00007f7570432048 R14: 00000000000d5761 R15: 00007ffe92384950