general protection fault in nf_nat_setup_info

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 399849e4 Linux 4.19.131
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17b7cc7b100000
kernel config: https://syzkaller.appspot.com/x/.config?x=eada6d424d8bae1d
dashboard link: https://syzkaller.appspot.com/bug?extid=e9ebb7c4f8359696c15b
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=151fe0a7100000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10e99a5b100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+e9ebb7...@syzkaller.appspotmail.com

audit: type=1400 audit(1593625703.581:8): avc: denied { execmem } for pid=6433 comm="syz-executor801" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 6433 Comm: syz-executor801 Not tainted 4.19.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline]
RIP: 0010:__nf_nat_l4proto_find net/netfilter/nf_nat_core.c:73 [inline]
RIP: 0010:get_unique_tuple net/netfilter/nf_nat_core.c:336 [inline]
RIP: 0010:nf_nat_setup_info+0x2f6/0x1f20 net/netfilter/nf_nat_core.c:431
Code: c1 ea 03 80 3c 02 00 0f 85 60 19 00 00 4a 8b 04 e5 60 7c ae 89 48 8d 1c d8 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 2c 19 00 00 48 8b 03 48 89 85 48 fe ff ff e8 f1
RSP: 0018:ffff8880a64beed0 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000030000000002 RCX: ffffffff85ea841d
RDX: 0000006000000000 RSI: ffffffff85ea7907 RDI: ffffffff89ae82a0
RBP: ffff8880a64bf0b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 00000000000000c8
R13: ffff8880a64bef70 R14: ffff888091791000 R15: 0000000000000000
FS: 0000000000907880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000300 CR3: 00000000a4ef8000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__nf_nat_alloc_null_binding+0x164/0x1d0 net/netfilter/nf_nat_core.c:490
nfnetlink_parse_nat_setup+0x53a/0x640 net/netfilter/nf_nat_core.c:882
ctnetlink_parse_nat_setup+0xb6/0x640 net/netfilter/nf_conntrack_netlink.c:1521
ctnetlink_setup_nat net/netfilter/nf_conntrack_netlink.c:1591 [inline]
ctnetlink_create_conntrack+0x4bb/0x12c0 net/netfilter/nf_conntrack_netlink.c:1984
ctnetlink_new_conntrack+0x4f3/0xde0 net/netfilter/nf_conntrack_netlink.c:2114
nfnetlink_rcv_msg+0xc4f/0xf60 net/netfilter/nfnetlink.c:228
netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455
nfnetlink_rcv+0x1b2/0x41b net/netfilter/nfnetlink.c:560
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x6bb/0xc40 net/netlink/af_netlink.c:1909
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xc3/0x120 net/socket.c:632
___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2115
__sys_sendmsg net/socket.c:2153 [inline]
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x132/0x220 net/socket.c:2160
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4402b9
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:00007ffc61abc4b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004402b9
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b40
R13: 0000000000401bd0 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace a781491dfd73b47c ]---
RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline]
RIP: 0010:__nf_nat_l4proto_find net/netfilter/nf_nat_core.c:73 [inline]
RIP: 0010:get_unique_tuple net/netfilter/nf_nat_core.c:336 [inline]
RIP: 0010:nf_nat_setup_info+0x2f6/0x1f20 net/netfilter/nf_nat_core.c:431
Code: c1 ea 03 80 3c 02 00 0f 85 60 19 00 00 4a 8b 04 e5 60 7c ae 89 48 8d 1c d8 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 2c 19 00 00 48 8b 03 48 89 85 48 fe ff ff e8 f1
RSP: 0018:ffff8880a64beed0 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000030000000002 RCX: ffffffff85ea841d
RDX: 0000006000000000 RSI: ffffffff85ea7907 RDI: ffffffff89ae82a0
RBP: ffff8880a64bf0b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 00000000000000c8
R13: ffff8880a64bef70 R14: ffff888091791000 R15: 0000000000000000
FS: 0000000000907880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000300 CR3: 00000000a4ef8000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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[syzbot]

syzbot suspects this issue was fixed by commit:

commit 289fe546ea16c2dcb57c5198c5a7b7387604530e
Author: Will McVicker <willmc...@google.com>
Date: Mon Aug 24 19:38:32 2020 +0000

netfilter: ctnetlink: add a range check for l3/l4 protonum

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16d746da500000
start commit: c14d30dc Linux 4.19.139
git tree: linux-4.19.y
kernel config: https://syzkaller.appspot.com/x/.config?x=93b261233af4719e
dashboard link: https://syzkaller.appspot.com/bug?extid=e9ebb7c4f8359696c15b
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1385b616900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=103d7fba900000

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

#syz fix: netfilter: ctnetlink: add a range check for l3/l4 protonum

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