============================================ WARNING: possible recursive locking detected 5.15.125-syzkaller #0 Not tainted -------------------------------------------- syz-executor.1/16373 is trying to acquire lock: ffff888079d51868 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:102 [inline] ffff888079d51868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x12f/0x1b60 fs/pipe.c:430 but task is already holding lock: ffff88801dbb6468 (&pipe->mutex/1){+.+.}-{3:3}, at: iter_file_splice_write+0x2ab/0xfa0 fs/splice.c:635 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&pipe->mutex/1); lock(&pipe->mutex/1); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by syz-executor.1/16373: #0: ffff88801dbb6468 (&pipe->mutex/1){+.+.}-{3:3}, at: iter_file_splice_write+0x2ab/0xfa0 fs/splice.c:635 stack backtrace: CPU: 1 PID: 16373 Comm: syz-executor.1 Not tainted 5.15.125-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2946 [inline] check_deadlock kernel/locking/lockdep.c:2989 [inline] validate_chain+0x46cf/0x58b0 kernel/locking/lockdep.c:3774 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 __pipe_lock fs/pipe.c:102 [inline] pipe_write+0x12f/0x1b60 fs/pipe.c:430 do_iter_readv_writev+0x594/0x7a0 do_iter_write+0x1ea/0x760 fs/read_write.c:855 iter_file_splice_write+0x806/0xfa0 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] do_splice+0xfe6/0x1790 fs/splice.c:1079 __do_splice fs/splice.c:1144 [inline] __do_sys_splice fs/splice.c:1350 [inline] __se_sys_splice+0x340/0x420 fs/splice.c:1332 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f953347bae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f95319fd0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f953359af80 RCX: 00007f953347bae9 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f95334c747a R08: 0000000080000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f953359af80 R15: 00007ffc0dc48178