2.6.28-stable review patch. If anyone has any objections, please let us know. ------------------ From: Jesper Dangaard Brouer [ Upstream commit 7b5e56f9d635643ad54f2f42e69ad16b80a2cff1 ] The UDP header pointer assignment must happen after calling pskb_may_pull(). As pskb_may_pull() can potentially alter the SKB buffer. This was exposted by running multicast traffic through the NIU driver, as it won't prepull the protocol headers into the linear area on receive. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/udp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1155,7 +1155,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, int proto) { struct sock *sk; - struct udphdr *uh = udp_hdr(skb); + struct udphdr *uh; unsigned short ulen; struct rtable *rt = (struct rtable*)skb->dst; __be32 saddr = ip_hdr(skb)->saddr; @@ -1168,6 +1168,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, if (!pskb_may_pull(skb, sizeof(struct udphdr))) goto drop; /* No space for header. */ + uh = udp_hdr(skb); ulen = ntohs(uh->len); if (ulen > skb->len) goto short_packet; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/