BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD 1a9fce067 P4D 1a9fce067 PUD 165b2f067 PMD 0 
Oops: 0010 [#1] SMP KASAN
CPU: 1 PID: 24367 Comm: syz-executor2 Not tainted 4.18.0-rc4-next-20180713+ #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:          (null)
Code: Bad RIP value.
RSP: 0018:ffff88019493ef08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffc90003e14000
RDX: 1ffff10038c1618e RSI: ffff88019493f188 RDI: ffff8801c60b0c70
RBP: ffff88019493f0f8 R08: ffff880191420000 R09: ffffed003ae151d0
R10: ffffed003ae151d0 R11: ffff8801d70a8e87 R12: ffff88019493f188
R13: ffff8801c60b0c70 R14: ffff8801c60b0c98 R15: 0000000000000080
FS:  00007fa5e2cc6700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001c2f2a000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 shrink_slab_memcg mm/vmscan.c:598 [inline]
 shrink_slab+0x861/0xa60 mm/vmscan.c:671
 shrink_node+0x429/0x16a0 mm/vmscan.c:2735
 shrink_zones mm/vmscan.c:2964 [inline]
 do_try_to_free_pages+0x3e7/0x1290 mm/vmscan.c:3026
 try_to_free_mem_cgroup_pages+0x49d/0xc90 mm/vmscan.c:3324
 memory_high_write+0x283/0x310 mm/memcontrol.c:5611
 cgroup_file_write+0x31f/0x840 kernel/cgroup/cgroup.c:3502
 kernfs_fop_write+0x2ba/0x480 fs/kernfs/file.c:316
 __vfs_write+0x117/0x9d0 fs/read_write.c:485
 vfs_write+0x1fc/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455ab9
Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fa5e2cc5c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa5e2cc66d4 RCX: 0000000000455ab9
RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000017
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c2c77 R14: 00000000004d4c80 R15: 0000000000000000
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
CR2: 0000000000000000
---[ end trace 566086ea798050dd ]---
RIP: 0010:          (null)
Code: Bad RIP value.
RSP: 0018:ffff88019493ef08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffc90003e14000
RDX: 1ffff10038c1618e RSI: ffff88019493f188 RDI: ffff8801c60b0c70
RBP: ffff88019493f0f8 R08: ffff880191420000 R09: ffffed003ae151d0
R10: ffffed003ae151d0 R11: ffff8801d70a8e87 R12: ffff88019493f188
R13: ffff8801c60b0c70 R14: ffff8801c60b0c98 R15: 0000000000000080
FS:  00007fa5e2cc6700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001c2f2a000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400