overlayfs: failed to resolve './file1': -2 ====================================================== WARNING: possible circular locking dependency detected 5.5.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/8808 is trying to acquire lock: ffff8880a1640860 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:65 [inline] ffff8880a1640860 (&pipe->mutex/1){+.+.}, at: pipe_lock+0x46/0x50 fs/pipe.c:73 but task is already holding lock: ffff888098d20428 (sb_writers#4){.+.+}, at: file_start_write include/linux/fs.h:2885 [inline] ffff888098d20428 (sb_writers#4){.+.+}, at: do_splice+0xdfb/0x1750 fs/splice.c:1169 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_writers#4){.+.+}: percpu_down_read include/linux/percpu-rwsem.h:40 [inline] __sb_start_write+0x18b/0x330 fs/super.c:1674 file_start_write include/linux/fs.h:2885 [inline] ovl_write_iter+0x80f/0xb10 fs/overlayfs/file.c:277 call_write_iter include/linux/fs.h:1902 [inline] new_sync_write+0x3fd/0x7e0 fs/read_write.c:483 __vfs_write+0x94/0x110 fs/read_write.c:496 __kernel_write+0x101/0x360 fs/read_write.c:515 write_pipe_buf+0x154/0x1f0 fs/splice.c:809 splice_from_pipe_feed fs/splice.c:512 [inline] __splice_from_pipe+0x2a7/0x770 fs/splice.c:636 splice_from_pipe+0xbb/0x120 fs/splice.c:671 default_file_splice_write+0x18/0x50 fs/splice.c:821 do_splice_from fs/splice.c:863 [inline] do_splice+0x9a2/0x1750 fs/splice.c:1170 __do_sys_splice fs/splice.c:1447 [inline] __se_sys_splice fs/splice.c:1427 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1427 do_syscall_64+0xca/0x5f0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&ovl_i_mutex_key[depth]){+.+.}: down_write+0x92/0x150 kernel/locking/rwsem.c:1534 inode_lock include/linux/fs.h:791 [inline] ovl_write_iter+0x12d/0xb10 fs/overlayfs/file.c:265 call_write_iter include/linux/fs.h:1902 [inline] new_sync_write+0x3fd/0x7e0 fs/read_write.c:483 __vfs_write+0x94/0x110 fs/read_write.c:496 __kernel_write+0x101/0x360 fs/read_write.c:515 write_pipe_buf+0x154/0x1f0 fs/splice.c:809 splice_from_pipe_feed fs/splice.c:512 [inline] __splice_from_pipe+0x2a7/0x770 fs/splice.c:636 splice_from_pipe+0xbb/0x120 fs/splice.c:671 default_file_splice_write+0x18/0x50 fs/splice.c:821 do_splice_from fs/splice.c:863 [inline] do_splice+0x9a2/0x1750 fs/splice.c:1170 __do_sys_splice fs/splice.c:1447 [inline] __se_sys_splice fs/splice.c:1427 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1427 do_syscall_64+0xca/0x5f0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&pipe->mutex/1){+.+.}: check_prev_add kernel/locking/lockdep.c:2475 [inline] check_prevs_add kernel/locking/lockdep.c:2580 [inline] validate_chain kernel/locking/lockdep.c:2970 [inline] __lock_acquire+0x2899/0x4ef0 kernel/locking/lockdep.c:3954 lock_acquire+0x194/0x410 kernel/locking/lockdep.c:4484 __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x155/0x1410 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 pipe_lock_nested fs/pipe.c:65 [inline] pipe_lock+0x46/0x50 fs/pipe.c:73 iter_file_splice_write+0x144/0xb70 fs/splice.c:709 do_splice_from fs/splice.c:863 [inline] do_splice+0x9a2/0x1750 fs/splice.c:1170 __do_sys_splice fs/splice.c:1447 [inline] __se_sys_splice fs/splice.c:1427 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1427 do_syscall_64+0xca/0x5f0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &pipe->mutex/1 --> &ovl_i_mutex_key[depth] --> sb_writers#4 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#4); lock(&ovl_i_mutex_key[depth]); lock(sb_writers#4); lock(&pipe->mutex/1); *** DEADLOCK *** 1 lock held by syz-executor.0/8808: #0: ffff888098d20428 (sb_writers#4){.+.+}, at: file_start_write include/linux/fs.h:2885 [inline] #0: ffff888098d20428 (sb_writers#4){.+.+}, at: do_splice+0xdfb/0x1750 fs/splice.c:1169 stack backtrace: CPU: 0 PID: 8808 Comm: syz-executor.0 Not tainted 5.5.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x12d/0x187 lib/dump_stack.c:118 print_circular_bug.isra.39.cold.58+0x15a/0x169 kernel/locking/lockdep.c:1684 check_noncircular+0x349/0x400 kernel/locking/lockdep.c:1808 check_prev_add kernel/locking/lockdep.c:2475 [inline] check_prevs_add kernel/locking/lockdep.c:2580 [inline] validate_chain kernel/locking/lockdep.c:2970 [inline] __lock_acquire+0x2899/0x4ef0 kernel/locking/lockdep.c:3954 lock_acquire+0x194/0x410 kernel/locking/lockdep.c:4484 __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x155/0x1410 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 pipe_lock_nested fs/pipe.c:65 [inline] pipe_lock+0x46/0x50 fs/pipe.c:73 iter_file_splice_write+0x144/0xb70 fs/splice.c:709 do_splice_from fs/splice.c:863 [inline] do_splice+0x9a2/0x1750 fs/splice.c:1170 __do_sys_splice fs/splice.c:1447 [inline] __se_sys_splice fs/splice.c:1427 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1427 do_syscall_64+0xca/0x5f0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a919 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2769c4dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045a919 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000100000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2769c4e6d4 R13: 00000000004cb466 R14: 00000000004e3f28 R15: 00000000ffffffff