WARNING: possible recursive locking detected 5.19.0-rc1-next-20220610-syzkaller #0 Not tainted -------------------------------------------- syz-executor.4/1317 is trying to acquire lock: ffff88807a897068 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline] ffff88807a897068 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x132/0x1bf0 fs/pipe.c:431 but task is already holding lock: ffff88801cbccc68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline] ffff88801cbccc68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock+0x5a/0x70 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.4/1317: #0: ffff88801cbccc68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline] #0: ffff88801cbccc68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock+0x5a/0x70 fs/pipe.c:90 stack backtrace: CPU: 1 PID: 1317 Comm: syz-executor.4 Not tainted 5.19.0-rc1-next-20220610-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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+0x1f5/0x3b4 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 __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+0x132/0x1bf0 fs/pipe.c:431 call_write_iter include/linux/fs.h:2057 [inline] do_iter_readv_writev+0x3d1/0x640 fs/read_write.c:742 do_iter_write+0x182/0x700 fs/read_write.c:868 vfs_iter_write+0x70/0xa0 fs/read_write.c:909 iter_file_splice_write+0x723/0xc70 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] do_splice+0xb57/0x1920 fs/splice.c:1079 __do_splice+0x134/0x250 fs/splice.c:1144 __do_sys_splice fs/splice.c:1350 [inline] __se_sys_splice fs/splice.c:1332 [inline] __x64_sys_splice+0x198/0x250 fs/splice.c:1332 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+0x46/0xb0 RIP: 0033:0x7f3643c89109 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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:00007f3644ed1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f3643d9bf60 RCX: 00007f3643c89109 RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f3643ce30ad R08: 0000000000017f41 R09: 0000000000000004 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc0d1eccef R14: 00007f3644ed1300 R15: 0000000000022000