Re: general protection fault in skb_segment

From: Willem de Bruijn
Date: Sun Dec 31 2017 - 04:18:38 EST


>> and with the reproducer, got:
>> [ 54.255469] Bogus gso_type: 7
>> [ 54.258801] Bogus gso_size: 63464
>> [ 54.262532] ------------[ cut here ]------------
>> [ 54.267703] syz0: caps=(0x00000800000058c1, 0x0000000000000000) len=32 data_len=0 gso_size=63464 gso_type=7 ip_summed0
>> [ 54.279777] WARNING: CPU: 1 PID: 13005 at /root/linux/net/core/dev.c:2600 skb_warn_bad_offload+0xd6/0xec
> I couldn't reproduce this call trace on net-next, maybe it's been fixed by:
> commit 8d74e9f88d65af8bb2e095aff506aa6eac755ada
> Author: Willem de Bruijn <willemb@xxxxxxxxxx>
> Date: Tue Dec 12 11:39:04 2017 -0500
>
> net: avoid skb_warn_bad_offload on IS_ERR

Yes, I forgot to mention that that has been fixed in net-next.

It does not address the crash, but does suppress the gratuitous
warning once we make segmentation return with error for bad
packets like these.