VFS: Found a V7 FS (block size = 512) on device loop2 ------------[ cut here ]------------ WARNING: CPU: 1 PID: 2727 at fs/inode.c:342 inc_nlink+0x113/0x130 syzkaller/managers/linux-4-14/kernel/fs/inode.c:342 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2727 Comm: syz-executor.2 Not tainted 4.14.218-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack syzkaller/managers/linux-4-14/kernel/lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 syzkaller/managers/linux-4-14/kernel/lib/dump_stack.c:58 panic+0x1f9/0x42d syzkaller/managers/linux-4-14/kernel/kernel/panic.c:183 __warn.cold+0x20/0x44 syzkaller/managers/linux-4-14/kernel/kernel/panic.c:547 report_bug+0x208/0x250 syzkaller/managers/linux-4-14/kernel/lib/bug.c:186 fixup_bug syzkaller/managers/linux-4-14/kernel/arch/x86/kernel/traps.c:177 [inline] fixup_bug syzkaller/managers/linux-4-14/kernel/arch/x86/kernel/traps.c:172 [inline] do_error_trap+0x195/0x2d0 syzkaller/managers/linux-4-14/kernel/arch/x86/kernel/traps.c:295 invalid_op+0x1b/0x40 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/entry_64.S:964 RIP: 0010:inc_nlink+0x113/0x130 syzkaller/managers/linux-4-14/kernel/fs/inode.c:342 RSP: 0018:ffff88805725fdf0 EFLAGS: 00010216 RAX: 0000000000040000 RBX: ffff888055dbc958 RCX: ffffc90007f89000 RDX: 00000000000005cd RSI: ffffffff818c2db3 RDI: ffff888055dbca30 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888055dbc9a0 R13: ffff88808e484b00 R14: ffffffff87aa3640 R15: 0000000000000000 inode_inc_link_count syzkaller/managers/linux-4-14/kernel/./include/linux/fs.h:2039 [inline] sysv_mkdir+0x21/0x120 syzkaller/managers/linux-4-14/kernel/fs/sysv/namei.c:136 vfs_mkdir+0x463/0x6e0 syzkaller/managers/linux-4-14/kernel/fs/namei.c:3849 SYSC_mkdirat syzkaller/managers/linux-4-14/kernel/fs/namei.c:3872 [inline] SyS_mkdirat+0x1fd/0x270 syzkaller/managers/linux-4-14/kernel/fs/namei.c:3856 do_syscall_64+0x1d5/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x465b09 RSP: 002b:00007fb3c2df2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000020002200 RDI: 0000000000000006 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffc070075cf R14: 00007fb3c2df2300 R15: 0000000000022000 Kernel Offset: disabled Rebooting in 86400 seconds..