minix_free_inode: bit 1 already cleared
VFS: Can't find a Minix filesystem V1 | V2 | V3 on device loop2.
MINIX-fs: mounting unchecked file system, running fsck is recommended
------------[ cut here ]------------
WARNING: CPU: 1 PID: 30609 at fs/inode.c:342 inc_nlink+0x113/0x130 fs/inode.c:342
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 30609 Comm: syz-executor.1 Not tainted 4.14.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 panic+0x1f9/0x42d kernel/panic.c:183
 __warn.cold+0x2f/0x30 kernel/panic.c:547
 report_bug+0x20a/0x248 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
VFS: Can't find a Minix filesystem V1 | V2 | V3 on device loop2.
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:inc_nlink+0x113/0x130 fs/inode.c:342
RSP: 0018:ffff88801ae0fdb0 EFLAGS: 00010216
RAX: 0000000000040000 RBX: ffff88808e97f0c0 RCX: ffffc90005afe000
RDX: 0000000000000915 RSI: ffffffff8190f153 RDI: ffff88808e97f198
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000002
R10: ffffed10035c1f8e R11: 0000000000000003 R12: ffff88808e97f108
R13: ffff888084914b80 R14: ffff888084914bd8 R15: 0000000000000000
 inode_inc_link_count include/linux/fs.h:2035 [inline]
 minix_mkdir+0x5a/0x160 fs/minix/namei.c:121
 vfs_mkdir+0x3af/0x620 fs/namei.c:3849
 SYSC_mkdirat fs/namei.c:3872 [inline]
 SyS_mkdirat fs/namei.c:3856 [inline]
 SYSC_mkdir fs/namei.c:3883 [inline]
 SyS_mkdir+0x1bc/0x210 fs/namei.c:3881
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007f6a6dc78c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00000000004f58e0 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000000000030 RDI: 00000000200000c0
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000734 R14: 00000000004c2300 R15: 00007f6a6dc796d4
Kernel Offset: disabled
Rebooting in 86400 seconds..