============================================ WARNING: possible recursive locking detected 6.0.0-rc1-syzkaller-00025-g274a2eebf80c #0 Not tainted -------------------------------------------- syz-executor392/3614 is trying to acquire lock: ffff888028310868 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline] ffff888028310868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x132/0x1be0 fs/pipe.c:431 but task is already holding lock: ffff888028310468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline] ffff888028310468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock fs/pipe.c:90 [inline] ffff888028310468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_wait_readable+0x39b/0x420 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-executor392/3614: #0: ffff888028310468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline] #0: ffff888028310468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock fs/pipe.c:90 [inline] #0: ffff888028310468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_wait_readable+0x39b/0x420 fs/pipe.c:1049 stack backtrace: CPU: 1 PID: 3614 Comm: syz-executor392 Not tainted 6.0.0-rc1-syzkaller-00025-g274a2eebf80c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain kernel/locking/lockdep.c:3816 [inline] __lock_acquire.cold+0x116/0x3a7 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 __pipe_lock fs/pipe.c:103 [inline] pipe_write+0x132/0x1be0 fs/pipe.c:431 call_write_iter include/linux/fs.h:2187 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:729 do_iter_write+0x182/0x700 fs/read_write.c:855 vfs_iter_write+0x70/0xa0 fs/read_write.c:896 iter_file_splice_write+0x718/0xc30 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] do_splice+0xb57/0x1920 fs/splice.c:1074 __do_splice+0x134/0x250 fs/splice.c:1139 __do_sys_splice fs/splice.c:1346 [inline] __se_sys_splice fs/splice.c:1328 [inline] __x64_sys_splice+0x198/0x250 fs/splice.c:1328 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f9fefdb0c99 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 14 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9fefd63308 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f9fefe39408 RCX: 00007f9fefdb0c99 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 00000000