vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
kasan: GPF could be caused by NULL-ptr deref or user memory access
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 16055 Comm: syz-executor.0 Not tainted 4.14.232-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880475cc500 task.stack: ffff888097270000
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
RIP: 0010:__list_del_entry_valid+0x81/0xf0 lib/list_debug.c:51
RSP: 0018:ffff888097277bd0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88809dd07a80 RCX: 0000000000000000
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88809dd07aa0
RBP: ffff88809dd07a98 R08: 0000000000000000 R09: 0000000000040057
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
R10: ffff8880475ccdb0 R11: ffff8880475cc500 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88809dd07aa0 R15: ffff8880b613c200
RIP: 0033:0x4665f9
FS:  00007f6531fda700(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
RSP: 002b:00007fb392b16188 EFLAGS: 00000246
CR2: 0000000000970004 CR3: 0000000033b31000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 ORIG_RAX: 00000000000000a5
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
 __list_del_entry include/linux/list.h:117 [inline]
 list_del include/linux/list.h:125 [inline]
 kernfs_kill_sb+0x5b/0x1b0 fs/kernfs/mount.c:365
RDX: 0000000020000280 RSI: 0000000020000100 RDI: 0000000000000000
 sysfs_kill_sb+0x1e/0x30 fs/sysfs/mount.c:53
RBP: 00007fb392b161d0 R08: 0000000000000000 R09: 0000000000000000
 deactivate_locked_super+0x6c/0xd0 fs/super.c:319
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
 kernfs_mount_ns+0x60f/0x7c0 fs/kernfs/mount.c:339
R13: 00007ffc8830dfef R14: 00007fb392b16300 R15: 0000000000022000
 sysfs_mount+0xa1/0x160 fs/sysfs/mount.c:39
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4665f9
RSP: 002b:00007f6531fda188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 0000000020000280 RSI: 0000000020000100 RDI: 0000000000000000
RBP: 00007f6531fda1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffd0bba5bef R14: 00007f6531fda300 R15: 0000000000022000
Code: c5 0f 84 aa ca ef 03 48 b8 00 02 00 00 00 00 ad de 49 39 c4 0f 84 ab ca ef 03 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75 51 49 8b 14 24 48 39 ea 0f 85 62 ca ef 03 49 8d 
RIP: __list_del_entry_valid+0x81/0xf0 lib/list_debug.c:51 RSP: ffff888097277bd0
---[ end trace 06bdc85d93b5dc7d ]---