Commit 405c92f7 authored by Hannes Frederic Sowa's avatar Hannes Frederic Sowa Committed by David S. Miller

ipv6: add defensive check for CHECKSUM_PARTIAL skbs in ip_fragment

CHECKSUM_PARTIAL skbs should never arrive in ip_fragment. If we get one
of those warn about them once and handle them gracefully by recalculating
the checksum.

Fixes: commit 32dce968 ("ipv6: Allow for partial checksums on non-ufo packets")
See-also: commit 72e843bb ("ipv6: ip6_fragment() should check CHECKSUM_PARTIAL")
Cc: Eric Dumazet <edumazet@google.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 682b1a9d
...@@ -603,6 +603,10 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, ...@@ -603,6 +603,10 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
&ipv6_hdr(skb)->saddr); &ipv6_hdr(skb)->saddr);
if (skb->ip_summed == CHECKSUM_PARTIAL &&
(err = skb_checksum_help(skb)))
goto fail;
hroom = LL_RESERVED_SPACE(rt->dst.dev); hroom = LL_RESERVED_SPACE(rt->dst.dev);
if (skb_has_frag_list(skb)) { if (skb_has_frag_list(skb)) {
int first_len = skb_pagelen(skb); int first_len = skb_pagelen(skb);
...@@ -731,10 +735,6 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, ...@@ -731,10 +735,6 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
} }
slow_path: slow_path:
if ((skb->ip_summed == CHECKSUM_PARTIAL) &&
skb_checksum_help(skb))
goto fail;
left = skb->len - hlen; /* Space per frame */ left = skb->len - hlen; /* Space per frame */
ptr = hlen; /* Where to start from */ ptr = hlen; /* Where to start from */
......
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