general protection fault in ipt_do_table

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2034d6f0 Linux 4.19.184
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=131a365ed00000
kernel config: https://syzkaller.appspot.com/x/.config?x=42af7daace4bc0cc
dashboard link: https://syzkaller.appspot.com/bug?extid=6acc97624a3f0f1b9f77

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6acc97...@syzkaller.appspotmail.com

netlink: 8 bytes leftover after parsing attributes in process `syz-executor.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: 0 PID: 17813 Comm: syz-executor.0 Not tainted 4.19.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:ipt_do_table+0x38d/0x1820 net/ipv4/netfilter/ip_tables.c:267
Code: 80 3c 11 00 0f 85 b5 13 00 00 48 8b 4c 24 28 89 c0 48 8b 51 38 48 8d 1c c2 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 7e 13 00 00 48 8b 03 48 89 44 24 58 0f 1f 44 00
RSP: 0018:ffff88803d27eee0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000070700 RCX: ffff8880001044c0
RDX: 000000000000e0e0 RSI: ffff888000104500 RDI: ffff8880001044f8
RBP: ffff88803d27f198 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff8880b4febc80
R13: ffff8880997e0300 R14: ffff88809e3932f0 R15: ffff8880b4febd44
FS: 00007f4c18dad700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000014a53ad CR3: 000000009162e000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ipt_mangle_out net/ipv4/netfilter/iptable_mangle.c:59 [inline]
iptable_mangle_hook+0x222/0x550 net/ipv4/netfilter/iptable_mangle.c:84
nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline]
nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:511
nf_hook include/linux/netfilter.h:244 [inline]
__ip_local_out+0x435/0x800 net/ipv4/ip_output.c:114
ip_local_out+0x26/0x170 net/ipv4/ip_output.c:123
__ip_queue_xmit+0x866/0x1b50 net/ipv4/ip_output.c:506
sctp_packet_transmit+0x1e21/0x3660 net/sctp/output.c:641
sctp_outq_flush_transports+0x19d/0x340 net/sctp/outqueue.c:1166
sctp_outq_flush net/sctp/outqueue.c:1214 [inline]
sctp_outq_uncork+0x185/0x200 net/sctp/outqueue.c:777
sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1328 [inline]
sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline]
sctp_do_sm+0x3c9d/0x5110 net/sctp/sm_sideeffect.c:1170
sctp_primitive_ABORT+0x9b/0xc0 net/sctp/primitive.c:119
sctp_close+0x240/0x7f0 net/sctp/socket.c:1558
inet_release+0xd7/0x1e0 net/ipv4/af_inet.c:427
__sock_release+0xcd/0x2a0 net/socket.c:579
sock_close+0x15/0x20 net/socket.c:1140
__fput+0x2ce/0x890 fs/file_table.c:278
task_work_run+0x148/0x1c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0xbf3/0x2be0 kernel/exit.c:870
do_group_exit+0x125/0x310 kernel/exit.c:967
get_signal+0x3f2/0x1f70 kernel/signal.c:2589
do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799
exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x466459
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4c18dad218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000056bf68 RCX: 0000000000466459
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf68
RBP: 000000000056bf60 R08: 000000000000000e R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf6c
R13: 00007ffdcb8124bf R14: 00007f4c18dad300 R15: 0000000000022000
Modules linked in:
---[ end trace 830ec7249824bac6 ]---
RIP: 0010:ipt_do_table+0x38d/0x1820 net/ipv4/netfilter/ip_tables.c:267
Code: 80 3c 11 00 0f 85 b5 13 00 00 48 8b 4c 24 28 89 c0 48 8b 51 38 48 8d 1c c2 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 7e 13 00 00 48 8b 03 48 89 44 24 58 0f 1f 44 00
RSP: 0018:ffff88803d27eee0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000070700 RCX: ffff8880001044c0
RDX: 000000000000e0e0 RSI: ffff888000104500 RDI: ffff8880001044f8
RBP: ffff88803d27f198 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff8880b4febc80
R13: ffff8880997e0300 R14: ffff88809e3932f0 R15: ffff8880b4febd44
FS: 00007f4c18dad700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000014a53ad CR3: 000000009162e000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.