1 files changed, 22 insertions, 58 deletions

diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 10842d5cf6e1..e14fca1fb003 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -78,24 +78,30 @@ static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)
 }
 
 #if IS_ENABLED(CONFIG_IPV6_MIP6)
-static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
-			       u8 **nexthdr)
+static int mip6_rthdr_offset(struct sk_buff *skb, u8 **nexthdr, int type)
 {
-	u16 offset = sizeof(struct ipv6hdr);
-	struct ipv6_opt_hdr *exthdr =
-				   (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
 	const unsigned char *nh = skb_network_header(skb);
-	unsigned int packet_len = skb_tail_pointer(skb) -
-		skb_network_header(skb);
+	unsigned int offset = sizeof(struct ipv6hdr);
+	unsigned int packet_len;
 	int found_rhdr = 0;
 
+	packet_len = skb_tail_pointer(skb) - nh;
 	*nexthdr = &ipv6_hdr(skb)->nexthdr;
 
-	while (offset + 1 <= packet_len) {
+	while (offset <= packet_len) {
+		struct ipv6_opt_hdr *exthdr;
+
 		switch (**nexthdr) {
 		case NEXTHDR_HOP:
 			break;
 		case NEXTHDR_ROUTING:
+			if (type == IPPROTO_ROUTING && offset + 3 <= packet_len) {
+				struct ipv6_rt_hdr *rt;
+
+				rt = (struct ipv6_rt_hdr *)(nh + offset);
+				if (rt->type != 0)
+					return offset;
+			}
 			found_rhdr = 1;
 			break;
 		case NEXTHDR_DEST:
@@ -116,59 +122,18 @@ static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
 			return offset;
 		}
 
-		offset += ipv6_optlen(exthdr);
-		*nexthdr = &exthdr->nexthdr;
-		exthdr = (struct ipv6_opt_hdr *)(nh + offset);
-	}
-
-	return offset;
-}
-
-static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb,
-			     u8 **nexthdr)
-{
-	u16 offset = sizeof(struct ipv6hdr);
-	struct ipv6_opt_hdr *exthdr =
-				   (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
-	const unsigned char *nh = skb_network_header(skb);
-	unsigned int packet_len = skb_tail_pointer(skb) -
-		skb_network_header(skb);
-	int found_rhdr = 0;
-
-	*nexthdr = &ipv6_hdr(skb)->nexthdr;
-
-	while (offset + 1 <= packet_len) {
-		switch (**nexthdr) {
-		case NEXTHDR_HOP:
-			break;
-		case NEXTHDR_ROUTING:
-			if (offset + 3 <= packet_len) {
-				struct ipv6_rt_hdr *rt;
-
-				rt = (struct ipv6_rt_hdr *)(nh + offset);
-				if (rt->type != 0)
-					return offset;
-			}
-			found_rhdr = 1;
-			break;
-		case NEXTHDR_DEST:
-			if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
-				return offset;
-
-			if (found_rhdr)
-				return offset;
-
-			break;
-		default:
-			return offset;
-		}
+		if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
+			return -EINVAL;
 
+		exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
+						 offset);
 		offset += ipv6_optlen(exthdr);
+		if (offset > IPV6_MAXPLEN)
+			return -EINVAL;
 		*nexthdr = &exthdr->nexthdr;
-		exthdr = (struct ipv6_opt_hdr *)(nh + offset);
 	}
 
-	return offset;
+	return -EINVAL;
 }
 #endif
 
@@ -177,9 +142,8 @@ static int xfrm6_hdr_offset(struct xfrm_state *x, struct sk_buff *skb, u8 **prev
 	switch (x->type->proto) {
 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 	case IPPROTO_DSTOPTS:
-		return mip6_destopt_offset(x, skb, prevhdr);
 	case IPPROTO_ROUTING:
-		return mip6_rthdr_offset(x, skb, prevhdr);
+		return mip6_rthdr_offset(skb, prevhdr, x->type->proto);
 #endif
 	default:
 		break;