diff options
| author | Li RongQing <roy.qing.li@gmail.com> | 2014-10-22 17:09:53 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-10-22 15:38:48 -0400 |
| commit | 789f202326640814c52f82e80cef3584d8254623 (patch) | |
| tree | 540a6b000c26f001178b237ccc41010fe8aee59e /net | |
| parent | 8751b12cd93cc37337256f650e309b8364d40b35 (diff) | |
xfrm6: fix a potential use after free in xfrm6_policy.c
pskb_may_pull() maybe change skb->data and make nh and exthdr pointer
oboslete, so recompute the nd and exthdr
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv6/xfrm6_policy.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c index ac49f84fe2c3..5f983644373a 100644 --- a/net/ipv6/xfrm6_policy.c +++ b/net/ipv6/xfrm6_policy.c @@ -170,8 +170,10 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) case IPPROTO_DCCP: if (!onlyproto && (nh + offset + 4 < skb->data || pskb_may_pull(skb, nh + offset + 4 - skb->data))) { - __be16 *ports = (__be16 *)exthdr; + __be16 *ports; + nh = skb_network_header(skb); + ports = (__be16 *)(nh + offset); fl6->fl6_sport = ports[!!reverse]; fl6->fl6_dport = ports[!reverse]; } @@ -180,8 +182,10 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) case IPPROTO_ICMPV6: if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) { - u8 *icmp = (u8 *)exthdr; + u8 *icmp; + nh = skb_network_header(skb); + icmp = (u8 *)(nh + offset); fl6->fl6_icmp_type = icmp[0]; fl6->fl6_icmp_code = icmp[1]; } @@ -192,8 +196,9 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) case IPPROTO_MH: if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) { struct ip6_mh *mh; - mh = (struct ip6_mh *)exthdr; + nh = skb_network_header(skb); + mh = (struct ip6_mh *)(nh + offset); fl6->fl6_mh_type = mh->ip6mh_type; } fl6->flowi6_proto = nexthdr; |