ipv4: Constrain UFO fragment sizes to multiples of 8 bytes
Because the ip fragment offset field counts 8-byte chunks, ip
fragments other than the last must contain a multiple of 8 bytes of
payload. ip_ufo_append_data wasn't respecting this constraint and,
depending on the MTU and ip option sizes, could create malformed
non-final fragments.
Google-Bug-Id: 5009328
Signed-off-by: Bill Sommerfeld <wsommerfeld@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index be27e60..ccaaa85 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -734,7 +734,7 @@
int getfrag(void *from, char *to, int offset, int len,
int odd, struct sk_buff *skb),
void *from, int length, int hh_len, int fragheaderlen,
- int transhdrlen, int mtu, unsigned int flags)
+ int transhdrlen, int maxfraglen, unsigned int flags)
{
struct sk_buff *skb;
int err;
@@ -767,7 +767,7 @@
skb->csum = 0;
/* specify the length of each IP datagram fragment */
- skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
+ skb_shinfo(skb)->gso_size = maxfraglen - fragheaderlen;
skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
__skb_queue_tail(queue, skb);
}
@@ -831,7 +831,7 @@
(rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len) {
err = ip_ufo_append_data(sk, queue, getfrag, from, length,
hh_len, fragheaderlen, transhdrlen,
- mtu, flags);
+ maxfraglen, flags);
if (err)
goto error;
return 0;