kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 12245 Comm: syz-executor.2 Not tainted 4.14.158-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880906d4140 task.stack: ffff888054a70000
RIP: 0010:cgroup_root_from_kf kernel/cgroup/cgroup.c:1178 [inline]
RIP: 0010:cgroup_kill_sb+0x2e/0x330 kernel/cgroup/cgroup.c:2035
RSP: 0018:ffff888054a77ac0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000fffffff4 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff81ac3a7c RDI: ffff8880961aedf0
RBP: ffff888054a77ae0 R08: ffff8880906d4140 R09: ffff8880906d49e0
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880961aedc0
R13: ffffffff87fa6e80 R14: ffff8880961aedc0 R15: dffffc0000000000
FS:  00007fa7c6523700(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f322000 CR3: 0000000094b12000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 deactivate_locked_super+0x74/0xe0 fs/super.c:319
 sget_userns+0x9d9/0xc30 fs/super.c:537
 kernfs_mount_ns+0xe9/0x790 fs/kernfs/mount.c:324
 kernfs_mount include/linux/kernfs.h:543 [inline]
 cgroup_do_mount+0x9e/0x270 kernel/cgroup/cgroup.c:1952
 cgroup_mount+0x26d/0x8c0 kernel/cgroup/cgroup.c:2019
 mount_fs+0x97/0x2a1 fs/super.c:1237
 vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x417/0x27d0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xab/0x120 fs/namespace.c:3072
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45a6f9
RSP: 002b:00007fa7c6522c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fa7c6522c90 RCX: 000000000045a6f9
kobject: 'loop1' (ffff8880a40fb4e0): kobject_uevent_env
RDX: 0000000020000200 RSI: 0000000020000100 RDI: 0000000000000000
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa7c65236d4
R13: 00000000004c7b37 R14: 00000000004de928 R15: 0000000000000006
Code: e5 41 55 41 54 49 89 fc 53 48 83 ec 08 e8 4b 28 06 00 4c 89 e7 e8 
kobject: 'loop1' (ffff8880a40fb4e0): fill_kobj_path: path = '/devices/virtual/block/loop1'
53 13 55 00 48 ba 00 00 00 00 00 fc ff df 48 89 c1 48 c1 e9 03 <80> 3c 11 00 0f 85 c4 02 00 00 48 8b 18 48 b8 00 00 00 00 00 fc 
RIP: cgroup_root_from_kf kernel/cgroup/cgroup.c:1178 [inline] RSP: ffff888054a77ac0
RIP: cgroup_kill_sb+0x2e/0x330 kernel/cgroup/cgroup.c:2035 RSP: ffff888054a77ac0
audit: type=1800 audit(1575819014.764:54): pid=12295 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="collect_data" cause="failed(directio)" comm="syz-executor.0" name="file0" dev="sda1" ino=17041 res=0
---[ end trace 5ba76d19bdfdd916 ]---
kobject: 'loop5' (ffff8880a423ce20): kobject_uevent_env