====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc6-syzkaller-00205-gd786aba32000 #0 Not tainted ------------------------------------------------------ syz.5.5944/26960 is trying to acquire lock: ffff88806238b9e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182 but task is already holding lock: ffff888058d91868 (&pipe->mutex){+.+.}-{4:4}, at: splice_file_to_pipe+0x2e/0x440 fs/splice.c:1286 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:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 anon_pipe_write+0x16a/0x1360 fs/pipe.c:458 __kernel_write_iter+0x3e9/0x860 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_do_expire_multi+0x5ca/0x9a0 fs/autofs/expire.c:593 autofs_root_ioctl+0x46/0x60 fs/autofs/root.c:910 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 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:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 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:1455 [inline] __traverse_mounts+0x305/0x5b0 fs/namei.c:1500 traverse_mounts fs/namei.c:1529 [inline] handle_mounts fs/namei.c:1632 [inline] step_into+0x534/0xf30 fs/namei.c:1976 lookup_last fs/namei.c:2639 [inline] path_lookupat+0x163/0x430 fs/namei.c:2663 filename_lookup+0x212/0x570 fs/namei.c:2692 kern_path+0x35/0x50 fs/namei.c:2825 lookup_bdev+0xc0/0x280 block/bdev.c:1205 resume_store+0x169/0x460 kernel/power/hibernate.c:1269 kernfs_fop_write_iter+0x375/0x4f0 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x548/0xa90 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/0x3b0 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:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:154 seq_read_iter+0x3f2/0xe10 fs/seq_file.c:225 copy_splice_read+0x552/0x9b0 fs/splice.c:363 do_splice_read fs/splice.c:979 [inline] splice_direct_to_actor+0x4a9/0xcc0 fs/splice.c:1083 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x181/0x270 fs/splice.c:1227 do_sendfile+0x4da/0x7e0 fs/read_write.c:1370 __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/0x3b0 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:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 seq_read_iter+0xb7/0xe10 fs/seq_file.c:182 copy_splice_read+0x552/0x9b0 fs/splice.c:363 do_splice_read fs/splice.c:979 [inline] splice_file_to_pipe+0x270/0x440 fs/splice.c:1289 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/0x3b0 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.5.5944/26960: #0: ffff888058d91868 (&pipe->mutex){+.+.}-{4:4}, at: splice_file_to_pipe+0x2e/0x440 fs/splice.c:1286 stack backtrace: CPU: 1 UID: 0 PID: 26960 Comm: syz.5.5944 Not tainted 6.16.0-rc6-syzkaller-00205-gd786aba32000 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2046 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 seq_read_iter+0xb7/0xe10 fs/seq_file.c:182 copy_splice_read+0x552/0x9b0 fs/splice.c:363 do_splice_read fs/splice.c:979 [inline] splice_file_to_pipe+0x270/0x440 fs/splice.c:1289 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/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f271178e9a9 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:00007f271254a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f27119b6160 RCX: 00007f271178e9a9 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000000 RBP: 00007f2711810ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f27119b6160 R15: 00007fff6bdb7468