============================================
WARNING: possible recursive locking detected
6.6.0-rc3-syzkaller-gbf6547d8715b #0 Not tainted
--------------------------------------------
syz-executor.2/9050 is trying to acquire lock:
ffff0000d25e8468 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline]
ffff0000d25e8468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x108/0x19c8 fs/pipe.c:432

but task is already holding lock:
ffff0000d25e8868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline]
ffff0000d25e8868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock+0x68/0x98 fs/pipe.c:90

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.2/9050:
 #0: ffff0000d25e8868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline]
 #0: ffff0000d25e8868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock+0x68/0x98 fs/pipe.c:90

stack backtrace:
CPU: 1 PID: 9050 Comm: syz-executor.2 Not tainted 6.6.0-rc3-syzkaller-gbf6547d8715b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 dump_stack+0x1c/0x28 lib/dump_stack.c:113
 print_deadlock_bug+0x4e4/0x660 kernel/locking/lockdep.c:3012
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain kernel/locking/lockdep.c:3855 [inline]
 __lock_acquire+0x5fd0/0x75e8 kernel/locking/lockdep.c:5136
 lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5753
 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799
 __pipe_lock fs/pipe.c:103 [inline]
 pipe_write+0x108/0x19c8 fs/pipe.c:432
 do_iter_write+0x65c/0xaa8 fs/read_write.c:860
 vfs_iter_write+0x88/0xac fs/read_write.c:901
 iter_file_splice_write+0x628/0xc58 fs/splice.c:736
 do_splice_from fs/splice.c:933 [inline]
 do_splice+0x100c/0x1d0c fs/splice.c:1292
 __do_splice fs/splice.c:1370 [inline]
 __do_sys_splice fs/splice.c:1586 [inline]
 __se_sys_splice fs/splice.c:1568 [inline]
 __arm64_sys_splice+0x490/0x804 fs/splice.c:1568
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x58/0x16c arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591