5 files changed, 31 insertions, 8 deletions

diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index f0328c7..53bf977 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1440,6 +1440,9 @@ static void __exit ip6_tables_fini(void)
  * If target header is found, its offset is set in *offset and return protocol
  * number. Otherwise, return -1.
  *
+ * If the first fragment doesn't contain the final protocol header or
+ * NEXTHDR_NONE it is considered invalid.
+ *
  * Note that non-1st fragment is special case that "the protocol number
  * of last header" is "next header" field in Fragment header. In this case,
  * *offset is meaningless and fragment offset is stored in *fragoff if fragoff
@@ -1463,12 +1466,12 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 		if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {
 			if (target < 0)
 				break;
-			return -1;
+			return -ENOENT;
 		}
 
 		hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
 		if (hp == NULL)
-			return -1;
+			return -EBADMSG;
 		if (nexthdr == NEXTHDR_FRAGMENT) {
 			unsigned short _frag_off, *fp;
 			fp = skb_header_pointer(skb,
@@ -1477,7 +1480,7 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 						sizeof(_frag_off),
 						&_frag_off);
 			if (fp == NULL)
-				return -1;
+				return -EBADMSG;
 
 			_frag_off = ntohs(*fp) & ~0x7;
 			if (_frag_off) {
@@ -1488,7 +1491,7 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 						*fragoff = _frag_off;
 					return hp->nexthdr;
 				}
-				return -1;
+				return -ENOENT;
 			}
 			hdrlen = 8;
 		} else if (nexthdr == NEXTHDR_AUTH)
diff --git a/net/ipv6/netfilter/ip6t_ah.c b/net/ipv6/netfilter/ip6t_ah.c
index ec1b160..4648664 100644
--- a/net/ipv6/netfilter/ip6t_ah.c
+++ b/net/ipv6/netfilter/ip6t_ah.c
@@ -54,9 +54,14 @@ match(const struct sk_buff *skb,
 	const struct ip6t_ah *ahinfo = matchinfo;
 	unsigned int ptr;
 	unsigned int hdrlen = 0;
+	int err;
 
-	if (ipv6_find_hdr(skb, &ptr, NEXTHDR_AUTH, NULL) < 0)
+	err = ipv6_find_hdr(skb, &ptr, NEXTHDR_AUTH, NULL);
+	if (err < 0) {
+		if (err != -ENOENT)
+			*hotdrop = 1;
 		return 0;
+	}
 
 	ah = skb_header_pointer(skb, ptr, sizeof(_ah), &_ah);
 	if (ah == NULL) {
diff --git a/net/ipv6/netfilter/ip6t_frag.c b/net/ipv6/netfilter/ip6t_frag.c
index 78d9c8b..cd22eaa 100644
--- a/net/ipv6/netfilter/ip6t_frag.c
+++ b/net/ipv6/netfilter/ip6t_frag.c
@@ -52,9 +52,14 @@ match(const struct sk_buff *skb,
 	struct frag_hdr _frag, *fh;
 	const struct ip6t_frag *fraginfo = matchinfo;
 	unsigned int ptr;
+	int err;
 
-	if (ipv6_find_hdr(skb, &ptr, NEXTHDR_FRAGMENT, NULL) < 0)
+	err = ipv6_find_hdr(skb, &ptr, NEXTHDR_FRAGMENT, NULL);
+	if (err < 0) {
+		if (err != -ENOENT)
+			*hotdrop = 1;
 		return 0;
+	}
 
 	fh = skb_header_pointer(skb, ptr, sizeof(_frag), &_frag);
 	if (fh == NULL) {
diff --git a/net/ipv6/netfilter/ip6t_hbh.c b/net/ipv6/netfilter/ip6t_hbh.c
index d32a205..3f25bab 100644
--- a/net/ipv6/netfilter/ip6t_hbh.c
+++ b/net/ipv6/netfilter/ip6t_hbh.c
@@ -65,9 +65,14 @@ match(const struct sk_buff *skb,
 	u8 _opttype, *tp = NULL;
 	u8 _optlen, *lp = NULL;
 	unsigned int optlen;
+	int err;
 
-	if (ipv6_find_hdr(skb, &ptr, match->data, NULL) < 0)
+	err = ipv6_find_hdr(skb, &ptr, match->data, NULL);
+	if (err < 0) {
+		if (err != -ENOENT)
+			*hotdrop = 1;
 		return 0;
+	}
 
 	oh = skb_header_pointer(skb, ptr, sizeof(_optsh), &_optsh);
 	if (oh == NULL) {
diff --git a/net/ipv6/netfilter/ip6t_rt.c b/net/ipv6/netfilter/ip6t_rt.c
index bcb2e16..54d7d14 100644
--- a/net/ipv6/netfilter/ip6t_rt.c
+++ b/net/ipv6/netfilter/ip6t_rt.c
@@ -58,9 +58,14 @@ match(const struct sk_buff *skb,
 	unsigned int hdrlen = 0;
 	unsigned int ret = 0;
 	struct in6_addr *ap, _addr;
+	int err;
 
-	if (ipv6_find_hdr(skb, &ptr, NEXTHDR_ROUTING, NULL) < 0)
+	err = ipv6_find_hdr(skb, &ptr, NEXTHDR_ROUTING, NULL);
+	if (err < 0) {
+		if (err != -ENOENT)
+			*hotdrop = 1;
 		return 0;
+	}
 
 	rh = skb_header_pointer(skb, ptr, sizeof(_route), &_route);
 	if (rh == NULL) {