Subject: general protection fault in xt_rateest_tg_checkentry

From: syzbot <[email-masked]>
Date: Thu, 26 Dec 2019 13:15:11 -0800

Hello,

syzbot found the following crash on:

HEAD commit:    46cf053e Linux 5.5-rc3
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11775799e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ed9d672709340e35
dashboard link: https://syzkaller.appspot.com/bug?extid=d7358a458d8a81aee898
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13713ec1e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1272ba49e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email-masked]

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: 9188 Comm: syz-executor670 Not tainted 5.5.0-rc3-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:199 [inline]
RIP: 0010:net_generic include/net/netns/generic.h:45 [inline]
RIP: 0010:xt_rateest_tg_checkentry+0x11d/0xb40  
net/netfilter/xt_RATEEST.c:109
Code: d9 f2 0d fb 45 84 f6 0f 84 08 07 00 00 e8 8b f1 0d fb 49 8d bd 68 13  
00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f  
85 f4 08 00 00 4d 8b ad 68 13 00 00 e8 cd 29 fa fa
RSP: 0018:ffffc90001df7788 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffc90001df7ae8 RCX: ffffffff8667437e
RDX: 000000000000026d RSI: ffffffff86673c65 RDI: 0000000000001368
RBP: ffffc90001df7848 R08: ffff888093e48540 R09: ffffed1015d2703d
R10: ffffed1015d2703c R11: ffff8880ae9381e3 R12: 000000000000002d
R13: 0000000000000000 R14: 0000000000000001 R15: ffffc90001df7820
FS:  0000000001250880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000820 CR3: 000000008f27a000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  xt_check_target+0x283/0x690 net/netfilter/x_tables.c:1019
  check_target net/ipv4/netfilter/arp_tables.c:399 [inline]
  find_check_entry net/ipv4/netfilter/arp_tables.c:422 [inline]
  translate_table+0x1005/0x1d70 net/ipv4/netfilter/arp_tables.c:572
  do_replace net/ipv4/netfilter/arp_tables.c:977 [inline]
  do_arpt_set_ctl+0x310/0x640 net/ipv4/netfilter/arp_tables.c:1456
  nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
  nf_setsockopt+0x77/0xd0 net/netfilter/nf_sockopt.c:115
  ip_setsockopt net/ipv4/ip_sockglue.c:1260 [inline]
  ip_setsockopt+0xdf/0x100 net/ipv4/ip_sockglue.c:1240
  udp_setsockopt+0x68/0xb0 net/ipv4/udp.c:2639
  sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3149
  __sys_setsockopt+0x261/0x4c0 net/socket.c:2117
  __do_sys_setsockopt net/socket.c:2133 [inline]
  __se_sys_setsockopt net/socket.c:2130 [inline]
  __x64_sys_setsockopt+0xbe/0x150 net/socket.c:2130
  do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4414d9
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:00007fff75392588 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004414d9
RDX: 0000000000000060 RSI: 0a02000000000000 RDI: 0000000000000003
RBP: 00000000006cb018 R08: 0000000000000530 R09: 00000000004002c8
R10: 0000000020000800 R11: 0000000000000246 R12: 0000000000402d60
R13: 0000000000402df0 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 6eeb34579322f089 ]---
RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline]
RIP: 0010:net_generic include/net/netns/generic.h:45 [inline]
RIP: 0010:xt_rateest_tg_checkentry+0x11d/0xb40  
net/netfilter/xt_RATEEST.c:109
Code: d9 f2 0d fb 45 84 f6 0f 84 08 07 00 00 e8 8b f1 0d fb 49 8d bd 68 13  
00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f  
85 f4 08 00 00 4d 8b ad 68 13 00 00 e8 cd 29 fa fa
RSP: 0018:ffffc90001df7788 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffc90001df7ae8 RCX: ffffffff8667437e
RDX: 000000000000026d RSI: ffffffff86673c65 RDI: 0000000000001368
RBP: ffffc90001df7848 R08: ffff888093e48540 R09: ffffed1015d2703d
R10: ffffed1015d2703c R11: ffff8880ae9381e3 R12: 000000000000002d
R13: 0000000000000000 R14: 0000000000000001 R15: ffffc90001df7820
FS:  0000000001250880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000820 CR3: 000000008f27a000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

---
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