============================================
WARNING: possible recursive locking detected
6.4.0-rc7-syzkaller-ge40939bbfc68 #0 Not tainted
--------------------------------------------
syz-executor.0/15838 is trying to acquire lock:
ffff0000caa3f468 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline]
ffff0000caa3f468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x108/0x19c8 fs/pipe.c:432
but task is already holding lock:
ffff0000ce621868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline]
ffff0000ce621868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock fs/pipe.c:90 [inline]
ffff0000ce621868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_wait_readable+0x320/0x468 fs/pipe.c:1054
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.0/15838:
#0: ffff0000ce621868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline]
#0: ffff0000ce621868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock fs/pipe.c:90 [inline]
#0: ffff0000ce621868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_wait_readable+0x320/0x468 fs/pipe.c:1054
stack backtrace:
CPU: 1 PID: 15838 Comm: syz-executor.0 Not tainted 6.4.0-rc7-syzkaller-ge40939bbfc68 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
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
__lock_acquire+0x62b8/0x7604
lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5705
__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/0xa80 fs/read_write.c:860
vfs_iter_write+0x88/0xac fs/read_write.c:901
iter_file_splice_write+0x610/0xc40 fs/splice.c:795
do_splice_from fs/splice.c:873 [inline]
do_splice+0x1040/0x1ba4 fs/splice.c:1182
__do_splice fs/splice.c:1260 [inline]
__do_sys_splice fs/splice.c:1471 [inline]
__se_sys_splice fs/splice.c:1453 [inline]
__arm64_sys_splice+0x490/0x804 fs/splice.c:1453
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191
el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591