[PATCH 4/5] xfrm4: Reload skb header pointers after calling pskb_may_pull.
From: Steffen Klassert <steffen.klassert@secunet.com>
Date: 2015-10-30 06:16:41
Subsystem:
networking [general], networking [ipsec], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Steffen Klassert, Herbert Xu, Linus Torvalds
A call to pskb_may_pull may change the pointers into the packet, so reload the pointers after the call. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> --- net/ipv4/xfrm4_policy.c | 33 ++++++++++++++++++++++++++------- 1 file changed, 26 insertions(+), 7 deletions(-)
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index e4d533c..269b137 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c@@ -129,7 +129,10 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) case IPPROTO_DCCP: if (xprth + 4 < skb->data || pskb_may_pull(skb, xprth + 4 - skb->data)) { - __be16 *ports = (__be16 *)xprth; + __be16 *ports; + + xprth = skb_network_header(skb) + iph->ihl * 4; + ports = (__be16 *)xprth; fl4->fl4_sport = ports[!!reverse]; fl4->fl4_dport = ports[!reverse];
@@ -139,7 +142,10 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) case IPPROTO_ICMP: if (xprth + 2 < skb->data || pskb_may_pull(skb, xprth + 2 - skb->data)) { - u8 *icmp = xprth; + u8 *icmp; + + xprth = skb_network_header(skb) + iph->ihl * 4; + icmp = xprth; fl4->fl4_icmp_type = icmp[0]; fl4->fl4_icmp_code = icmp[1];
@@ -149,7 +155,10 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) case IPPROTO_ESP: if (xprth + 4 < skb->data || pskb_may_pull(skb, xprth + 4 - skb->data)) { - __be32 *ehdr = (__be32 *)xprth; + __be32 *ehdr; + + xprth = skb_network_header(skb) + iph->ihl * 4; + ehdr = (__be32 *)xprth; fl4->fl4_ipsec_spi = ehdr[0]; }
@@ -158,7 +167,10 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) case IPPROTO_AH: if (xprth + 8 < skb->data || pskb_may_pull(skb, xprth + 8 - skb->data)) { - __be32 *ah_hdr = (__be32 *)xprth; + __be32 *ah_hdr; + + xprth = skb_network_header(skb) + iph->ihl * 4; + ah_hdr = (__be32 *)xprth; fl4->fl4_ipsec_spi = ah_hdr[1]; }
@@ -167,7 +179,10 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) case IPPROTO_COMP: if (xprth + 4 < skb->data || pskb_may_pull(skb, xprth + 4 - skb->data)) { - __be16 *ipcomp_hdr = (__be16 *)xprth; + __be16 *ipcomp_hdr; + + xprth = skb_network_header(skb) + iph->ihl * 4; + ipcomp_hdr = (__be16 *)xprth; fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); }
@@ -176,8 +191,12 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) case IPPROTO_GRE: if (xprth + 12 < skb->data || pskb_may_pull(skb, xprth + 12 - skb->data)) { - __be16 *greflags = (__be16 *)xprth; - __be32 *gre_hdr = (__be32 *)xprth; + __be16 *greflags; + __be32 *gre_hdr; + + xprth = skb_network_header(skb) + iph->ihl * 4; + greflags = (__be16 *)xprth; + gre_hdr = (__be32 *)xprth; if (greflags[0] & GRE_KEY) { if (greflags[0] & GRE_CSUM)
--
1.9.1