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authorHannes Frederic Sowa <hannes@stressinduktion.org>2013-09-21 06:27:00 +0200
committerDavid S. Miller <davem@davemloft.net>2013-09-24 11:43:05 -0400
commit2811ebac2521ceac84f2bdae402455baa6a7fb47 (patch)
tree96bbd5a84db928a2186c7b4f3a4500edab6dc1b9 /net
parent3db9180213af6aa54effc2b94bc9090dc1f68673 (diff)
downloadlinux-2811ebac2521ceac84f2bdae402455baa6a7fb47.tar.gz
ipv6: udp packets following an UFO enqueued packet need also be handled by UFO
In the following scenario the socket is corked: If the first UDP packet is larger then the mtu we try to append it to the write queue via ip6_ufo_append_data. A following packet, which is smaller than the mtu would be appended to the already queued up gso-skb via plain ip6_append_data. This causes random memory corruptions. In ip6_ufo_append_data we also have to be careful to not queue up the same skb multiple times. So setup the gso frame only when no first skb is available. This also fixes a shortcoming where we add the current packet's length to cork->length but return early because of a packet > mtu with dontfrag set (instead of sutracting it again). Found with trinity. Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv6/ip6_output.c53
1 files changed, 22 insertions, 31 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 3a692d529163..a54c45ce4a48 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1015,6 +1015,8 @@ static inline int ip6_ufo_append_data(struct sock *sk,
* udp datagram
*/
if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
+ struct frag_hdr fhdr;
+
skb = sock_alloc_send_skb(sk,
hh_len + fragheaderlen + transhdrlen + 20,
(flags & MSG_DONTWAIT), &err);
@@ -1036,12 +1038,6 @@ static inline int ip6_ufo_append_data(struct sock *sk,
skb->protocol = htons(ETH_P_IPV6);
skb->ip_summed = CHECKSUM_PARTIAL;
skb->csum = 0;
- }
-
- err = skb_append_datato_frags(sk,skb, getfrag, from,
- (length - transhdrlen));
- if (!err) {
- struct frag_hdr fhdr;
/* Specify the length of each IPv6 datagram fragment.
* It has to be a multiple of 8.
@@ -1052,15 +1048,10 @@ static inline int ip6_ufo_append_data(struct sock *sk,
ipv6_select_ident(&fhdr, rt);
skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
__skb_queue_tail(&sk->sk_write_queue, skb);
-
- return 0;
}
- /* There is not enough support do UPD LSO,
- * so follow normal path
- */
- kfree_skb(skb);
- return err;
+ return skb_append_datato_frags(sk, skb, getfrag, from,
+ (length - transhdrlen));
}
static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
@@ -1227,27 +1218,27 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
* --yoshfuji
*/
- cork->length += length;
- if (length > mtu) {
- int proto = sk->sk_protocol;
- if (dontfrag && (proto == IPPROTO_UDP || proto == IPPROTO_RAW)){
- ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen);
- return -EMSGSIZE;
- }
-
- if (proto == IPPROTO_UDP &&
- (rt->dst.dev->features & NETIF_F_UFO)) {
+ if ((length > mtu) && dontfrag && (sk->sk_protocol == IPPROTO_UDP ||
+ sk->sk_protocol == IPPROTO_RAW)) {
+ ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen);
+ return -EMSGSIZE;
+ }
- err = ip6_ufo_append_data(sk, getfrag, from, length,
- hh_len, fragheaderlen,
- transhdrlen, mtu, flags, rt);
- if (err)
- goto error;
- return 0;
- }
+ skb = skb_peek_tail(&sk->sk_write_queue);
+ cork->length += length;
+ if (((length > mtu) ||
+ (skb && skb_is_gso(skb))) &&
+ (sk->sk_protocol == IPPROTO_UDP) &&
+ (rt->dst.dev->features & NETIF_F_UFO)) {
+ err = ip6_ufo_append_data(sk, getfrag, from, length,
+ hh_len, fragheaderlen,
+ transhdrlen, mtu, flags, rt);
+ if (err)
+ goto error;
+ return 0;
}
- if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
+ if (!skb)
goto alloc_new_skb;
while (length > 0) {