BUG: unable to handle kernel paging request in cgroup_mt_destroy_v1

[syzbot]

Hello,

syzbot hit the following crash on upstream commit
3da90b159b146672f830bcd2489dd3a1f4e9e089 (Wed Jan 31 03:07:32 2018 +0000)
Merge tag 'f2fs-for-4.16-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

So far this crash happened 3 times on net-next, upstream.
C reproducer is attached.
syzkaller reproducer is attached.
Raw console output is attached.
compiler: gcc (GCC) 7.1.1 20170620
.config is attached.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+eeed26...@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for
details.
If you forward the report, please keep this part and the footer.

audit: type=1400 audit(1517426494.787:7): avc: denied { map } for
pid=4176 comm="syzkaller493328" path="/root/syzkaller493328633" dev="sda1"
ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
BUG: unable to handle kernel paging request at ffffffffffffff6d
IP: css_put include/linux/cgroup.h:386 [inline]
IP: cgroup_put include/linux/cgroup.h:415 [inline]
IP: cgroup_mt_destroy_v1+0xe5/0x310 net/netfilter/xt_cgroup.c:102
PGD 6a25067 P4D 6a25067 PUD 6a27067 PMD 0
Oops: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4176 Comm: syzkaller493328 Not tainted 4.15.0+ #288
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:css_put include/linux/cgroup.h:386 [inline]
RIP: 0010:cgroup_put include/linux/cgroup.h:415 [inline]
RIP: 0010:cgroup_mt_destroy_v1+0xe5/0x310 net/netfilter/xt_cgroup.c:102
RSP: 0018:ffff8801b19e7958 EFLAGS: 00010246
RAX: 0000000000000008 RBX: 1ffff1003633cf2b RCX: ffffffff847188c6
RDX: 0000000000000000 RSI: ffffffff8709b900 RDI: ffffffffffffff6d
RBP: ffff8801b19e79e0 R08: 1ffff1003633cef9 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffffffff01
R13: ffff8801b19e79b8 R14: dffffc0000000000 R15: ffffffff84718810
FS: 0000000000c16880(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffff6d CR3: 00000001b1f38004 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
cleanup_match+0x14e/0x220 net/ipv6/netfilter/ip6_tables.c:481
cleanup_entry+0xcb/0x350 net/ipv4/netfilter/ip_tables.c:646
__do_replace+0x7d7/0xa90 net/ipv4/netfilter/ip_tables.c:1091
do_replace net/ipv4/netfilter/ip_tables.c:1147 [inline]
do_ipt_set_ctl+0x40f/0x5f0 net/ipv4/netfilter/ip_tables.c:1677
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0xa1/0xb0 net/ipv4/ip_sockglue.c:1256
tcp_setsockopt+0x82/0xd0 net/ipv4/tcp.c:2875
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968
SYSC_setsockopt net/socket.c:1831 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1810
entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x4408a9
RSP: 002b:00007ffddd061cc8 EFLAGS: 00000207 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 00000000004408a9
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000004
RBP: faaff2414ccfc19e R08: 00000000000012f0 R09: 0000000000000000
R10: 000000002000b000 R11: 0000000000000207 R12: 886f734548d4d66b
R13: ffffffffffffff01 R14: 0000000000000000 R15: 0000000000000000
Code: 6c 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48
89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 a6 01 00 00 <41> f6 44 24
6c 01 74 2e e8 be 06 ff fc 48 b8 00 00 00 00 00 fc
RIP: css_put include/linux/cgroup.h:386 [inline] RSP: ffff8801b19e7958
RIP: cgroup_put include/linux/cgroup.h:415 [inline] RSP: ffff8801b19e7958
RIP: cgroup_mt_destroy_v1+0xe5/0x310 net/netfilter/xt_cgroup.c:102 RSP:
ffff8801b19e7958
CR2: ffffffffffffff6d
---[ end trace bfd8c145aa41ae03 ]---


---
This bug is generated by a dumb bot. It may contain errors.
See https://goo.gl/tpsmEJ for details.
Direct all questions to syzk...@googlegroups.com.

syzbot will keep track of this bug report.
If you forgot to add the Reported-by tag, once the fix for this bug is
merged
into any tree, please reply to this email with:
#syz fix: exact-commit-title
If you want to test a patch for this bug, please reply with:
#syz test: git://repo/address.git branch
and provide the patch inline or as an attachment.
To mark this as a duplicate of another syzbot report, please reply with:
#syz dup: exact-subject-of-another-report
If it's a one-off invalid bug report, please reply with:
#syz invalid
Note: if the crash happens again, it will cause creation of a new bug
report.
Note: all commands must start from beginning of the line in the email body.

[Eric Biggers]

This was fixed by commit ba7cd5d95f25cc6:

#syz fix: netfilter: xt_cgroup: initialize info->priv in cgroup_mt_check_v1()

- Eric