====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.7.10104/665 is trying to acquire lock: ffff88802f3720a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 but task is already holding lock: ffff88807346fc68 (&pipe->mutex){+.+.}-{4:4}, at: splice_file_to_pipe+0x2e/0x440 fs/splice.c:1289 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&pipe->mutex){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 anon_pipe_write+0x15d/0x1460 fs/pipe.c:458 __kernel_write_iter+0x481/0x910 fs/read_write.c:619 __kernel_write+0xef/0x150 fs/read_write.c:639 autofs_write fs/autofs/waitq.c:57 [inline] autofs_notify_daemon+0x748/0xe50 fs/autofs/waitq.c:164 autofs_wait+0x11dc/0x1870 fs/autofs/waitq.c:426 autofs_mount_wait+0x16b/0x330 fs/autofs/root.c:255 autofs_d_automount+0x393/0x720 fs/autofs/root.c:401 follow_automount fs/namei.c:1459 [inline] __traverse_mounts+0x301/0x5e0 fs/namei.c:1512 traverse_mounts fs/namei.c:1541 [inline] handle_mounts fs/namei.c:1644 [inline] step_into+0x4f2/0xe80 fs/namei.c:1989 walk_component fs/namei.c:2157 [inline] link_path_walk+0x77b/0xea0 fs/namei.c:2519 path_openat+0x28c/0x3830 fs/namei.c:4130 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 -> #2 (&sbi->pipe_mutex){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 autofs_write fs/autofs/waitq.c:55 [inline] autofs_notify_daemon+0x735/0xe50 fs/autofs/waitq.c:164 autofs_wait+0x11dc/0x1870 fs/autofs/waitq.c:426 autofs_mount_wait+0x16b/0x330 fs/autofs/root.c:255 autofs_d_automount+0x393/0x720 fs/autofs/root.c:401 follow_automount fs/namei.c:1459 [inline] __traverse_mounts+0x301/0x5e0 fs/namei.c:1512 traverse_mounts fs/namei.c:1541 [inline] handle_mounts fs/namei.c:1644 [inline] step_into+0x4f2/0xe80 fs/namei.c:1989 lookup_last fs/namei.c:2652 [inline] path_lookupat+0x163/0x430 fs/namei.c:2676 filename_lookup+0x212/0x570 fs/namei.c:2705 kern_path+0x35/0x50 fs/namei.c:2863 lookup_bdev+0xc0/0x280 block/bdev.c:1205 resume_store+0x169/0x460 kernel/power/hibernate.c:1309 kernfs_fop_write_iter+0x3af/0x540 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 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 -> #1 (&of->mutex){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 traverse+0x164/0x580 fs/seq_file.c:106 seq_read_iter+0xd08/0xe20 fs/seq_file.c:195 copy_splice_read+0x5d4/0xa50 fs/splice.c:363 do_splice_read fs/splice.c:982 [inline] splice_direct_to_actor+0x4a9/0xcc0 fs/splice.c:1086 do_splice_direct_actor fs/splice.c:1204 [inline] do_splice_direct+0x181/0x270 fs/splice.c:1230 do_sendfile+0x4da/0x7e0 fs/read_write.c:1370 __do_sys_sendfile64 fs/read_write.c:1425 [inline] __se_sys_sendfile64+0xd9/0x190 fs/read_write.c:1417 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 -> #0 (&p->lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 copy_splice_read+0x5d4/0xa50 fs/splice.c:363 do_splice_read fs/splice.c:982 [inline] splice_file_to_pipe+0x273/0x440 fs/splice.c:1292 do_sendfile+0x475/0x7e0 fs/read_write.c:1376 __do_sys_sendfile64 fs/read_write.c:1431 [inline] __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1417 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 other info that might help us debug this: Chain exists of: &p->lock --> &sbi->pipe_mutex --> &pipe->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex); lock(&sbi->pipe_mutex); lock(&pipe->mutex); lock(&p->lock); *** DEADLOCK *** 1 lock held by syz.7.10104/665: #0: ffff88807346fc68 (&pipe->mutex){+.+.}-{4:4}, at: splice_file_to_pipe+0x2e/0x440 fs/splice.c:1289 stack backtrace: CPU: 1 UID: 0 PID: 665 Comm: syz.7.10104 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 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+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 copy_splice_read+0x5d4/0xa50 fs/splice.c:363 do_splice_read fs/splice.c:982 [inline] splice_file_to_pipe+0x273/0x440 fs/splice.c:1292 do_sendfile+0x475/0x7e0 fs/read_write.c:1376 __do_sys_sendfile64 fs/read_write.c:1431 [inline] __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1417 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: 0033:0x7f7424b8eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f74259cf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f7424de5fa0 RCX: 00007f7424b8eec9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000000 RBP: 00007f7424c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000010001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7424de6038 R14: 00007f7424de5fa0 R15: 00007fffae485528