============================================ WARNING: possible recursive locking detected 6.1.47-syzkaller #0 Not tainted -------------------------------------------- syz-executor.1/5204 is trying to acquire lock: ffff888082cb4068 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline] ffff888082cb4068 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x12d/0x1af0 fs/pipe.c:431 but task is already holding lock: ffff888080e7bc68 (&pipe->mutex/1){+.+.}-{3:3}, at: iter_file_splice_write+0x2ab/0xfa0 fs/splice.c:632 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.1/5204: #0: ffff888080e7bc68 (&pipe->mutex/1){+.+.}-{3:3}, at: iter_file_splice_write+0x2ab/0xfa0 fs/splice.c:632 stack backtrace: CPU: 0 PID: 5204 Comm: syz-executor.1 Not tainted 6.1.47-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2991 [inline] check_deadlock kernel/locking/lockdep.c:3034 [inline] validate_chain+0x4726/0x58e0 kernel/locking/lockdep.c:3819 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 __mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 __pipe_lock fs/pipe.c:103 [inline] pipe_write+0x12d/0x1af0 fs/pipe.c:431 do_iter_write+0x6e6/0xc50 fs/read_write.c:861 iter_file_splice_write+0x806/0xfa0 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] do_splice+0xfdb/0x1790 fs/splice.c:1074 __do_splice fs/splice.c:1139 [inline] __do_sys_splice fs/splice.c:1346 [inline] __se_sys_splice+0x340/0x420 fs/splice.c:1328 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ffb4147cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffb422580c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007ffb4159c050 RCX: 00007ffb4147cae9 RDX: 000000000000000c RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007ffb414c847a R08: 0000000000008001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007ffb4159c050 R15: 00007ffc2358f868