1 files changed, 19 insertions, 18 deletions

diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c
index 140748debc4a..49e31e4ae7b7 100644
--- a/net/ipv6/exthdrs_core.c
+++ b/net/ipv6/exthdrs_core.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * IPv6 library code, needed by static components when full IPv6 support is
  * not configured or static.
@@ -82,7 +83,7 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
 		if (nexthdr == NEXTHDR_NONE)
 			return -1;
 		hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
-		if (hp == NULL)
+		if (!hp)
 			return -1;
 		if (nexthdr == NEXTHDR_FRAGMENT) {
 			__be16 _frag_off, *fp;
@@ -91,7 +92,7 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
 							       frag_off),
 						sizeof(_frag_off),
 						&_frag_off);
-			if (fp == NULL)
+			if (!fp)
 				return -1;
 
 			*frag_offp = *fp;
@@ -99,7 +100,7 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
 				break;
 			hdrlen = 8;
 		} else if (nexthdr == NEXTHDR_AUTH)
-			hdrlen = (hp->hdrlen+2)<<2;
+			hdrlen = ipv6_authlen(hp);
 		else
 			hdrlen = ipv6_optlen(hp);
 
@@ -112,7 +113,7 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
 }
 EXPORT_SYMBOL(ipv6_skip_exthdr);
 
-int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
+int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type)
 {
 	const unsigned char *nh = skb_network_header(skb);
 	int packet_len = skb_tail_pointer(skb) - skb_network_header(skb);
@@ -142,6 +143,8 @@ int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
 			optlen = 1;
 			break;
 		default:
+			if (len < 2)
+				goto bad;
 			optlen = nh[offset + 1] + 2;
 			if (optlen > len)
 				goto bad;
@@ -161,7 +164,7 @@ EXPORT_SYMBOL_GPL(ipv6_find_tlv);
  * if target < 0. "last header" is transport protocol header, ESP, or
  * "No next header".
  *
- * Note that *offset is used as input/output parameter. an if it is not zero,
+ * Note that *offset is used as input/output parameter, and if it is not zero,
  * then it must be a valid offset to an inner IPv6 header. This can be used
  * to explore inner IPv6 header, eg. ICMPv6 error messages.
  *
@@ -187,7 +190,6 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 {
 	unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
 	u8 nexthdr = ipv6_hdr(skb)->nexthdr;
-	unsigned int len;
 	bool found;
 
 	if (fragoff)
@@ -197,14 +199,11 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 		struct ipv6hdr _ip6, *ip6;
 
 		ip6 = skb_header_pointer(skb, *offset, sizeof(_ip6), &_ip6);
-		if (!ip6 || (ip6->version != 6)) {
-			printk(KERN_ERR "IPv6 header not found\n");
+		if (!ip6 || (ip6->version != 6))
 			return -EBADMSG;
-		}
 		start = *offset + sizeof(struct ipv6hdr);
 		nexthdr = ip6->nexthdr;
 	}
-	len = skb->len - start;
 
 	do {
 		struct ipv6_opt_hdr _hdr, *hp;
@@ -212,13 +211,13 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 		found = (nexthdr == target);
 
 		if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {
-			if (target < 0)
+			if (target < 0 || found)
 				break;
 			return -ENOENT;
 		}
 
 		hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
-		if (hp == NULL)
+		if (!hp)
 			return -EBADMSG;
 
 		if (nexthdr == NEXTHDR_ROUTING) {
@@ -226,7 +225,7 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 
 			rh = skb_header_pointer(skb, start, sizeof(_rh),
 						&_rh);
-			if (rh == NULL)
+			if (!rh)
 				return -EBADMSG;
 
 			if (flags && (*flags & IP6_FH_F_SKIP_RH) &&
@@ -245,7 +244,7 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 							       frag_off),
 						sizeof(_frag_off),
 						&_frag_off);
-			if (fp == NULL)
+			if (!fp)
 				return -EBADMSG;
 
 			_frag_off = ntohs(*fp) & ~0x7;
@@ -257,19 +256,22 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 						*fragoff = _frag_off;
 					return hp->nexthdr;
 				}
-				return -ENOENT;
+				if (!found)
+					return -ENOENT;
+				if (fragoff)
+					*fragoff = _frag_off;
+				break;
 			}
 			hdrlen = 8;
 		} else if (nexthdr == NEXTHDR_AUTH) {
 			if (flags && (*flags & IP6_FH_F_AUTH) && (target < 0))
 				break;
-			hdrlen = (hp->hdrlen + 2) << 2;
+			hdrlen = ipv6_authlen(hp);
 		} else
 			hdrlen = ipv6_optlen(hp);
 
 		if (!found) {
 			nexthdr = hp->nexthdr;
-			len -= hdrlen;
 			start += hdrlen;
 		}
 	} while (!found);
@@ -278,4 +280,3 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 	return nexthdr;
 }
 EXPORT_SYMBOL(ipv6_find_hdr);
-