diff options
Diffstat (limited to 'net/ipv6/ah6.c')
| -rw-r--r-- | net/ipv6/ah6.c | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c index 76f7a2de9108..c96f7e0d0a48 100644 --- a/net/ipv6/ah6.c +++ b/net/ipv6/ah6.c @@ -232,26 +232,28 @@ static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *des * Rearrange the destination address in @iph and the addresses in @rthdr * so that they appear in the order they will at the final destination. * See Appendix A2 of RFC 2402 for details. + * + * Return: 0 on success, -EINVAL if segments_left exceeds the number of + * addresses described by hdrlen. */ -static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) +static int ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) { - int segments, segments_left; + unsigned int segments, segments_left; struct in6_addr *addrs; struct in6_addr final_addr; segments_left = rthdr->segments_left; if (segments_left == 0) - return; - rthdr->segments_left = 0; + return 0; - /* The value of rthdr->hdrlen has been verified either by the system - * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming - * packets. So we can assume that it is even and that segments is - * greater than or equal to segments_left. - * - * For the same reason we can assume that this option is of type 0. + /* Raw locally generated packets can reach AH6 without the invariant + * required by the rt0-style address rearrangement below. */ segments = rthdr->hdrlen >> 1; + if (segments_left > segments) + return -EINVAL; + + rthdr->segments_left = 0; addrs = ((struct rt0_hdr *)rthdr)->addr; final_addr = addrs[segments - 1]; @@ -261,6 +263,8 @@ static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) addrs[0] = iph->daddr; iph->daddr = final_addr; + + return 0; } static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) @@ -273,6 +277,7 @@ static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) } exthdr = { .iph = iph }; char *end = exthdr.raw + len; int nexthdr = iph->nexthdr; + int err; exthdr.iph++; @@ -292,7 +297,9 @@ static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) break; case NEXTHDR_ROUTING: - ipv6_rearrange_rthdr(iph, exthdr.rth); + err = ipv6_rearrange_rthdr(iph, exthdr.rth); + if (err) + return err; break; default: |