general protection fault in nft_chain_parse_hook

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: db5b9190 Linux 4.19.96
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17c97ffee00000
kernel config: https://syzkaller.appspot.com/x/.config?x=7a24894346f71303
dashboard link: https://syzkaller.appspot.com/bug?extid=2cdb4059d1cb0c55b98b
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=169f8f15e00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16fd6daee00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+2cdb40...@syzkaller.appspotmail.com

audit: type=1400 audit(1579199041.014:36): avc: denied { map } for
pid=8198 comm="syz-executor671" path="/root/syz-executor671249523"
dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
kasan: CONFIG_KASAN_INLINE enabled
audit: type=1400 audit(1579199041.014:37): avc: denied { create } for
pid=8198 comm="syz-executor671"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_netfilter_socket permissive=1
kasan: GPF could be caused by NULL-ptr deref or user memory access
audit: type=1400 audit(1579199041.014:38): avc: denied { write } for
pid=8198 comm="syz-executor671"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_netfilter_socket permissive=1
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8198 Comm: syz-executor671 Not tainted 4.19.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:nft_chain_parse_hook+0x37c/0x8c0
net/netfilter/nf_tables_api.c:1511
Code: 00 e8 98 7d 6a fb 41 83 fd 05 0f 87 30 04 00 00 e8 09 7c 6a fb 48 8d
7b 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84
c0 74 08 3c 03 0f 8e 77 04 00 00 44 89 e9 be 01 00
RSP: 0018:ffff8880916ff200 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff860099a8
RDX: 0000000000000003 RSI: ffffffff860099b7 RDI: 0000000000000018
RBP: ffff8880916ff2f0 R08: ffff88808ac48040 R09: 0000000000000000
R10: ffffed10122dfe4c R11: ffff8880916ff267 R12: ffff8880916ff370
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880916ff2c8
FS: 0000000001f2b880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560989fab1b0 CR3: 000000009f6c0000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
nf_tables_addchain.constprop.0+0x1a6/0xf90
net/netfilter/nf_tables_api.c:1592
nf_tables_newchain+0xf54/0x14d0 net/netfilter/nf_tables_api.c:1867
nfnetlink_rcv_batch+0xef6/0x1750 net/netfilter/nfnetlink.c:430
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:540 [inline]
nfnetlink_rcv+0x3ed/0x460 net/netfilter/nfnetlink.c:558
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x53a/0x730 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:632
___sys_sendmsg+0x803/0x920 net/socket.c:2115
__sys_sendmsg+0x105/0x1d0 net/socket.c:2153
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440559
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc25717898 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440559
RDX: 0000000004000000 RSI: 000000002000d400 RDI: 0000000000000004
RBP: 00000000006ca018 R08: 0000000000000003 R09: 00000000004002c8
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000401de0
R13: 0000000000401e70 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 13c6606361f2d9a2 ]---
RIP: 0010:nft_chain_parse_hook+0x37c/0x8c0
net/netfilter/nf_tables_api.c:1511
Code: 00 e8 98 7d 6a fb 41 83 fd 05 0f 87 30 04 00 00 e8 09 7c 6a fb 48 8d
7b 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84
c0 74 08 3c 03 0f 8e 77 04 00 00 44 89 e9 be 01 00
RSP: 0018:ffff8880916ff200 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff860099a8
RDX: 0000000000000003 RSI: ffffffff860099b7 RDI: 0000000000000018
RBP: ffff8880916ff2f0 R08: ffff88808ac48040 R09: 0000000000000000
R10: ffffed10122dfe4c R11: ffff8880916ff267 R12: ffff8880916ff370
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880916ff2c8
FS: 0000000001f2b880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560989fab1b0 CR3: 000000009f6c0000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This bug is generated by a bot. It may contain errors.
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[syzbot]

syzbot suspects this bug was fixed by commit:

commit 1f7a1bcd27c388b4cc286e943218c69db2d3ba71
Author: Pablo Neira Ayuso <pa...@netfilter.org>
Date: Tue Jan 21 15:07:00 2020 +0000

netfilter: nf_tables: add __nft_chain_type_get()

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=141e72c3e00000
start commit: db5b9190 Linux 4.19.96
git tree: linux-4.19.y

kernel config: https://syzkaller.appspot.com/x/.config?x=7a24894346f71303
dashboard link: https://syzkaller.appspot.com/bug?extid=2cdb4059d1cb0c55b98b

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=169f8f15e00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16fd6daee00000

If the result looks correct, please mark the bug fixed by replying with:

#syz fix: netfilter: nf_tables: add __nft_chain_type_get()

For information about bisection process see: https://goo.gl/tpsmEJ#bisection