diff options
| -rw-r--r-- | net/ipv6/exthdrs.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index c486b8e1817f..aa0a51e64682 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -153,6 +153,7 @@ static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb) while (len > 0) { int optlen = nh[off + 1] + 2; + int i; switch (nh[off]) { case IPV6_TLV_PAD0: @@ -160,6 +161,21 @@ static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb) break; case IPV6_TLV_PADN: + /* RFC 2460 states that the purpose of PadN is + * to align the containing header to multiples + * of 8. 7 is therefore the highest valid value. + * See also RFC 4942, Section 2.1.9.5. + */ + if (optlen > 7) + goto bad; + /* RFC 4942 recommends receiving hosts to + * actively check PadN payload to contain + * only zeroes. + */ + for (i = 2; i < optlen; i++) { + if (nh[off + i] != 0) + goto bad; + } break; default: /* Other TLV code so scan list */ |