Re: [PATCH net] net: drop pulled SKB_GSO_FRAGLIST skb

[Willem de Bruijn]

shiming.cheng@ wrote:
> From: Shiming Cheng <shiming.cheng@xxxxxxxxxxxx>
> 
> A SKB_GSO_FRAGLIST skb without GSO_BY_FRAGS is
> expected to have all segments except the last
> to be gso_size long. If this does not hold, the
> skb has been modified and the fraglist gso integrity
> is lost. Drop the packet, as it cannot be segmented
> correctly by skb_segment_list.
> 
> The skb could be salvaged. By linearizing, dropping
> the SKB_GSO_FRAGLIST bit and entering the normal
> skb_segment path rather than the skb_segment_list path.
> 
> That choice is currently made in the protocol caller,
> __udp_gso_segment. It's not trivial to add such a
> backup path here. So let's add this backstop against
> kernel crashes.
> 
> Fixes: 3a1296a38d0c ("net: Support GRO/GSO fraglist chaining.")
> Signed-off-by: Shiming Cheng <shiming.cheng@xxxxxxxxxxxx>
> Signed-off-by: Lena Wang <lena.wang@xxxxxxxxxxxx>

Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx>