overlayfs: at least 2 lowerdir are needed while upperdir nonexistent
EXT4-fs (loop4): orphan cleanup on readonly fs
------------[ cut here ]------------
WARNING: CPU: 0 PID: 13069 at fs/inode.c:286 drop_nlink.cold+0x11/0x41 fs/inode.c:286
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 13069 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0
audit: type=1804 audit(1663104801.840:288): pid=13048 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.3" name="/root/syzkaller-testdir3656713503/syzkaller.AmTEMB/1216/bus" dev="sda1" ino=14257 res=1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 panic+0x26a/0x50e kernel/panic.c:186
EXT4-fs error (device loop4): __ext4_iget:5088: inode #3: block 4194304: comm syz-executor.4: invalid block
EXT4-fs (loop4): Remounting filesystem read-only
 __warn.cold+0x20/0x5a kernel/panic.c:541
EXT4-fs error (device loop4): ext4_quota_enable:5846: comm syz-executor.4: Bad quota inode # 3
 report_bug+0x262/0x2b0 lib/bug.c:183
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
EXT4-fs warning (device loop4): ext4_enable_quotas:5883: Failed to enable quota tracking (type=0, err=-117). Please run e2fsck to fix.
EXT4-fs (loop4): Cannot turn on quotas: error -117
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:drop_nlink.cold+0x11/0x41 fs/inode.c:286
EXT4-fs (loop4): mounted filesystem without journal. Opts: errors=remount-ro,
Code: f9 e8 9c bd 6d f9 48 c7 c7 80 a8 74 88 e8 fb ee fe ff 0f 0b e9 9f 50 b4 f9 e8 84 bd 6d f9 48 c7 c7 80 b0 74 88 e8 e3 ee fe ff <0f> 0b b8 ff ff 37 00 4c 89 e2 48 c1 ea 03 48 c1 e0 2a 0f b6 04 02
RSP: 0018:ffff888054207cc0 EFLAGS: 00010286
RAX: 0000000000000024 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000002a052 RSI: ffffffff814dff01 RDI: ffffed100a840f8a
RBP: ffff888053653a60 R08: 0000000000000024 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff888053653aa8
R13: ffff88808ddbe000 R14: ffff888054207d58 R15: ffff888053653a60
 ovl_do_remove+0x8b3/0xdb0 fs/overlayfs/dir.c:867
 vfs_unlink+0x27d/0x4e0 fs/namei.c:4002
audit: type=1804 audit(1663104801.910:289): pid=13059 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.3" name="/root/syzkaller-testdir3656713503/syzkaller.AmTEMB/1216/bus" dev="sda1" ino=14257 res=1
 do_unlinkat+0x3b8/0x660 fs/namei.c:4065
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f762521c409
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:00007f7623b4f168 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007f762532f120 RCX: 00007f762521c409
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000440
RBP: 00007f7625277367 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffb61e45cf R14: 00007f7623b4f300 R15: 0000000000022000
Kernel Offset: disabled
Rebooting in 86400 seconds..