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From: Cong Wang <xiyou.wangcong@gmail.com>
Newsgroups: linux.kernel
Subject: Re: [BUG] skb corruption and kernel panic at forwarding with fragmentation
Date: Wed, 06 Jan 2016 21:00:03 +0100
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On Wed, Jan 6, 2016 at 11:15 AM, Konstantin Khlebnikov <koct9i@gmail.com> wrote:
> Looks like this happens because ip_options_fragment() relies on
> correct ip options length in ip control block in skb. But in
> ip_finish_output_gso() control block in segments is reused by
> skb_gso_segment(). following ip_fragment() sees some garbage.
>
> In my case there was no ip options but length becomes non-zero and
> ip_options_fragment() picked some bytes from payload and decides to
> fill huge range with IPOPT_NOOP (1). One of that ones flipped nr_frags
> in skb_shared_info at the end of data =)
>

Hmm, it looks like SKB_GSO_CB should be cleared after skb_gso_segment()
since all the gso information should be saved in shared_info after it finishes.

Does a memset(0) on SKB_GSO_CB after skb_gso_segment() work as well?
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