diff options
| author | Eric Dumazet | 2012-09-25 22:01:28 +0200 |
|---|---|---|
| committer | David S. Miller | 2012-09-25 16:04:44 -0400 |
| commit | 96af69ea2a83d292238bdba20e4508ee967cf8cb (patch) | |
| tree | bea3edef18f4817519b1084efd6e66c62d9a4f31 | |
| parent | 78cc88c408675a7cc42e6d7402c9d90080e0b841 (diff) | |
ipv6: mip6: fix mip6_mh_filter()
mip6_mh_filter() should not modify its input, or else its caller
would need to recompute ipv6_hdr() if skb->head is reallocated.
Use skb_header_pointer() instead of pskb_may_pull()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv6/mip6.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c index 5b087c31d87b..0f9bdc5ee9f3 100644 --- a/net/ipv6/mip6.c +++ b/net/ipv6/mip6.c @@ -86,28 +86,30 @@ static int mip6_mh_len(int type) static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb) { - struct ip6_mh *mh; + struct ip6_mh _hdr; + const struct ip6_mh *mh; - if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) || - !pskb_may_pull(skb, (skb_transport_offset(skb) + - ((skb_transport_header(skb)[1] + 1) << 3)))) + mh = skb_header_pointer(skb, skb_transport_offset(skb), + sizeof(_hdr), &_hdr); + if (!mh) return -1; - mh = (struct ip6_mh *)skb_transport_header(skb); + if (((mh->ip6mh_hdrlen + 1) << 3) > skb->len) + return -1; if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) { LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n", mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type)); - mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) - - skb_network_header(skb))); + mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_hdrlen) + + skb_network_header_len(skb)); return -1; } if (mh->ip6mh_proto != IPPROTO_NONE) { LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n", mh->ip6mh_proto); - mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) - - skb_network_header(skb))); + mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_proto) + + skb_network_header_len(skb)); return -1; } |