diff options
| -rw-r--r-- | net/ipv6/exthdrs.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 50ec95f9aeeb..6447dc49429f 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -144,6 +144,7 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb) const unsigned char *nh = skb_network_header(skb); int off = skb_network_header_len(skb); int len = (skb_transport_header(skb)[1] + 1) << 3; + int padlen = 0; if (skb_transport_offset(skb) + len > skb_headlen(skb)) goto bad; @@ -158,6 +159,9 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb) switch (nh[off]) { case IPV6_TLV_PAD1: optlen = 1; + padlen++; + if (padlen > 7) + goto bad; break; case IPV6_TLV_PADN: @@ -166,7 +170,8 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb) * of 8. 7 is therefore the highest valid value. * See also RFC 4942, Section 2.1.9.5. */ - if (optlen > 7) + padlen += optlen; + if (padlen > 7) goto bad; /* RFC 4942 recommends receiving hosts to * actively check PadN payload to contain @@ -195,11 +200,19 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb) if (ip6_tlvopt_unknown(skb, off) == 0) return false; } + padlen = 0; break; } off += optlen; len -= optlen; } + /* This case will not be caught by above check since its padding + * length is smaller than 7: + * 1 byte NH + 1 byte Length + 6 bytes Padding + */ + if ((padlen == 6) && ((off - skb_network_header_len(skb)) == 8)) + goto bad; + if (len == 0) return true; bad: |