============================================ WARNING: possible recursive locking detected 6.1.70-syzkaller #0 Not tainted -------------------------------------------- syz-executor.3/11909 is trying to acquire lock: ffff00012c483868 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline] ffff00012c483868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x114/0x1990 fs/pipe.c:431 but task is already holding lock: ffff0000dda5bc68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline] ffff0000dda5bc68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock fs/pipe.c:90 [inline] ffff0000dda5bc68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_wait_readable+0x320/0x468 fs/pipe.c:1049 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.3/11909: #0: ffff0000dda5bc68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline] #0: ffff0000dda5bc68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock fs/pipe.c:90 [inline] #0: ffff0000dda5bc68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_wait_readable+0x320/0x468 fs/pipe.c:1049 stack backtrace: CPU: 0 PID: 11909 Comm: syz-executor.3 Not tainted 6.1.70-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __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+0x6310/0x7680 kernel/locking/lockdep.c:5049 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 __pipe_lock fs/pipe.c:103 [inline] pipe_write+0x114/0x1990 fs/pipe.c:431 do_iter_write+0x534/0x964 fs/read_write.c:861 vfs_iter_write+0x88/0xac fs/read_write.c:902 iter_file_splice_write+0x618/0xc48 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] do_splice+0xfd0/0x1898 fs/splice.c:1074 __do_splice fs/splice.c:1139 [inline] __do_sys_splice fs/splice.c:1346 [inline] __se_sys_splice fs/splice.c:1328 [inline] __arm64_sys_splice+0x50c/0x7fc fs/splice.c:1328 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585