ipv4: 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.
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: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 0b02417..4233cbe 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -533,6 +533,11 @@
dev = rt->dst.dev;
+ /* for offloaded checksums cleanup checksum before fragmentation */
+ if (skb->ip_summed == CHECKSUM_PARTIAL &&
+ (err = skb_checksum_help(skb)))
+ goto fail;
+
/*
* Point into the IP datagram header.
*/
@@ -657,9 +662,6 @@
}
slow_path:
- /* for offloaded checksums cleanup checksum before fragmentation */
- if ((skb->ip_summed == CHECKSUM_PARTIAL) && skb_checksum_help(skb))
- goto fail;
iph = ip_hdr(skb);
left = skb->len - hlen; /* Space per frame */