============================================ WARNING: possible recursive locking detected 6.1.0-rc5-syzkaller-00144-g84368d882b96 #0 Not tainted -------------------------------------------- syz-executor.0/29313 is trying to acquire lock: ffff888074f20c68 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline] ffff888074f20c68 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_write+0x136/0x1bf0 fs/pipe.c:431 but task is already holding lock: ffff88807d555868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline] ffff88807d555868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock+0x5e/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.0/29313: #0: ffff88807d555868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline] #0: ffff88807d555868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock+0x5e/0x70 fs/pipe.c:90 stack backtrace: CPU: 0 PID: 29313 Comm: syz-executor.0 Not tainted 6.1.0-rc5-syzkaller-00144-g84368d882b96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2990 [inline] check_deadlock kernel/locking/lockdep.c:3033 [inline] validate_chain kernel/locking/lockdep.c:3818 [inline] __lock_acquire.cold+0x116/0x3a7 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1360 kernel/locking/mutex.c:747 __pipe_lock fs/pipe.c:103 [inline] pipe_write+0x136/0x1bf0 fs/pipe.c:431 call_write_iter include/linux/fs.h:2191 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735 do_iter_write+0x182/0x700 fs/read_write.c:861 vfs_iter_write+0x74/0xa0 fs/read_write.c:902 iter_file_splice_write+0x745/0xc90 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] do_splice+0xb5b/0x1930 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+0x19c/0x250 fs/splice.c:1328 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f070808b639 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:00007f0708e15168 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f07081ac050 RCX: 00007f070808b639 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f07080e6ae9 R08: 000000000002ffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffebdd1f8ff R14: 00007f0708e15300 R15: 0000000000022000