PATCH [1/1] ipv4: Prevent malformed UFO fragments in ip_append_page

[Steven Caron]

As  the ip fragment offset field counts 8-byte chunks, non-final ip
fragments must be multiples of 8 bytes of payload. Depending  on
the mtu and ip option sizes, ip_append_page wasn't respecting this,
notably when running NFS under UDP.

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 124bf0a..21ec54e 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1239,7 +1239,7 @@ ssize_t   ip_append_page(struct sock *sk, struct flowi4 
*fl4, struct page *page,
if (skb->ip_summed != CHECKSUM_PARTIAL)
return -EOPNOTSUPP;

-   skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
+   skb_shinfo(skb)->gso_size = maxfraglen - fragheaderlen;
skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
}
cork->length += size;

Re: PATCH [1/1] ipv4: Prevent malformed UFO fragments in ip_append_page

[David Miller]

From: Steven Caron 
Date: Fri, 10 Jun 2016 19:21:26 +

> As  the ip fragment offset field counts 8-byte chunks, non-final ip
> fragments must be multiples of 8 bytes of payload. Depending  on
> the mtu and ip option sizes, ip_append_page wasn't respecting this,
> notably when running NFS under UDP.
> 

All patch submissions need a proper signoff.

Please resubmit this properly.