============================================
WARNING: possible recursive locking detected
5.15.127-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.5/30233 is trying to acquire lock:
ffff00011bb98c68 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:102 [inline]
ffff00011bb98c68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x10c/0x1a4c fs/pipe.c:430

but task is already holding lock:
ffff00011bb99068 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:81 [inline]
ffff00011bb99068 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock+0x68/0x98 fs/pipe.c:89

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.5/30233:
 #0: ffff00011bb99068 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:81 [inline]
 #0: ffff00011bb99068 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock+0x68/0x98 fs/pipe.c:89

stack backtrace:
CPU: 0 PID: 30233 Comm: syz-executor.5 Not tainted 5.15.127-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 __lock_acquire+0x62b4/0x7620 kernel/locking/lockdep.c:5011
 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5622
 __mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
 __pipe_lock fs/pipe.c:102 [inline]
 pipe_write+0x10c/0x1a4c fs/pipe.c:430
 do_iter_readv_writev+0x420/0x5f8
 do_iter_write+0x1b8/0x664 fs/read_write.c:855
 vfs_iter_write+0x88/0xac fs/read_write.c:896
 iter_file_splice_write+0x618/0xc48 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 do_splice+0x11b4/0x1a0c fs/splice.c:1079
 __do_splice fs/splice.c:1144 [inline]
 __do_sys_splice fs/splice.c:1350 [inline]
 __se_sys_splice fs/splice.c:1332 [inline]
 __arm64_sys_splice+0x564/0x8b0 fs/splice.c:1332
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584