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| author | Steffen Klassert <steffen.klassert@secunet.com> | 2015-10-23 07:31:23 +0200 |
|---|---|---|
| committer | Steffen Klassert <steffen.klassert@secunet.com> | 2015-10-23 07:31:23 +0200 |
| commit | 1a14f1e5550a341f76e5c8f596e9b5f8a886dfbc (patch) | |
| tree | 51d56a04d8d955f1eb661d239f4ec01f226b0ae5 /net/ipv4/xfrm4_policy.c | |
| parent | xfrm: Fix unaligned access to stats in copy_to_user_state() (diff) | |
| download | linux-1a14f1e5550a341f76e5c8f596e9b5f8a886dfbc.tar.xz linux-1a14f1e5550a341f76e5c8f596e9b5f8a886dfbc.zip | |
xfrm4: Fix header checks in _decode_session4.
We skip the header informations if the data pointer points
already behind the header in question for some protocols.
This is because we call pskb_may_pull with a negative value
converted to unsigened int from pskb_may_pull in this case.
Skipping the header informations can lead to incorrect policy
lookups, so fix it by a check of the data pointer position
before we call pskb_may_pull.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/ipv4/xfrm4_policy.c')
| -rw-r--r-- | net/ipv4/xfrm4_policy.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c index 75e8d48c03fb..e4d533c6c796 100644 --- a/net/ipv4/xfrm4_policy.c +++ b/net/ipv4/xfrm4_policy.c @@ -137,7 +137,8 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) break; case IPPROTO_ICMP: - if (pskb_may_pull(skb, xprth + 2 - skb->data)) { + if (xprth + 2 < skb->data || + pskb_may_pull(skb, xprth + 2 - skb->data)) { u8 *icmp = xprth; fl4->fl4_icmp_type = icmp[0]; @@ -146,7 +147,8 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) break; case IPPROTO_ESP: - if (pskb_may_pull(skb, xprth + 4 - skb->data)) { + if (xprth + 4 < skb->data || + pskb_may_pull(skb, xprth + 4 - skb->data)) { __be32 *ehdr = (__be32 *)xprth; fl4->fl4_ipsec_spi = ehdr[0]; @@ -154,7 +156,8 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) break; case IPPROTO_AH: - if (pskb_may_pull(skb, xprth + 8 - skb->data)) { + if (xprth + 8 < skb->data || + pskb_may_pull(skb, xprth + 8 - skb->data)) { __be32 *ah_hdr = (__be32 *)xprth; fl4->fl4_ipsec_spi = ah_hdr[1]; @@ -162,7 +165,8 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) break; case IPPROTO_COMP: - if (pskb_may_pull(skb, xprth + 4 - skb->data)) { + if (xprth + 4 < skb->data || + pskb_may_pull(skb, xprth + 4 - skb->data)) { __be16 *ipcomp_hdr = (__be16 *)xprth; fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); @@ -170,7 +174,8 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) break; case IPPROTO_GRE: - if (pskb_may_pull(skb, xprth + 12 - skb->data)) { + if (xprth + 12 < skb->data || + pskb_may_pull(skb, xprth + 12 - skb->data)) { __be16 *greflags = (__be16 *)xprth; __be32 *gre_hdr = (__be32 *)xprth; |