diff options
| -rw-r--r-- | include/net/dropreason-core.h | 6 | ||||
| -rw-r--r-- | include/net/ipv6.h | 3 | ||||
| -rw-r--r-- | net/ipv6/exthdrs_core.c | 7 | ||||
| -rw-r--r-- | net/ipv6/ip6_input.c | 5 | ||||
| -rw-r--r-- | net/ipv6/ip6_tunnel.c | 4 |
5 files changed, 25 insertions, 0 deletions
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h index e0ca3904ff8e..2f312d1f67d6 100644 --- a/include/net/dropreason-core.h +++ b/include/net/dropreason-core.h @@ -99,6 +99,7 @@ FN(FRAG_TOO_FAR) \ FN(TCP_MINTTL) \ FN(IPV6_BAD_EXTHDR) \ + FN(IPV6_TOO_MANY_EXTHDRS) \ FN(IPV6_NDISC_FRAG) \ FN(IPV6_NDISC_HOP_LIMIT) \ FN(IPV6_NDISC_BAD_CODE) \ @@ -494,6 +495,11 @@ enum skb_drop_reason { SKB_DROP_REASON_TCP_MINTTL, /** @SKB_DROP_REASON_IPV6_BAD_EXTHDR: Bad IPv6 extension header. */ SKB_DROP_REASON_IPV6_BAD_EXTHDR, + /** + * @SKB_DROP_REASON_IPV6_TOO_MANY_EXTHDRS: Number of IPv6 extension + * headers in the packet exceeds IP6_MAX_EXT_HDRS_CNT. + */ + SKB_DROP_REASON_IPV6_TOO_MANY_EXTHDRS, /** @SKB_DROP_REASON_IPV6_NDISC_FRAG: invalid frag (suppress_frag_ndisc). */ SKB_DROP_REASON_IPV6_NDISC_FRAG, /** @SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT: invalid hop limit. */ diff --git a/include/net/ipv6.h b/include/net/ipv6.h index d042afe7a245..1dec81faff28 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -90,6 +90,9 @@ struct ip_tunnel_info; #define IP6_DEFAULT_MAX_DST_OPTS_LEN INT_MAX /* No limit */ #define IP6_DEFAULT_MAX_HBH_OPTS_LEN INT_MAX /* No limit */ +/* Hard limit on traversed IPv6 extension headers */ +#define IP6_MAX_EXT_HDRS_CNT 12 + /* * Addr type * diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c index 49e31e4ae7b7..9d06d487e8b1 100644 --- a/net/ipv6/exthdrs_core.c +++ b/net/ipv6/exthdrs_core.c @@ -73,6 +73,7 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp, __be16 *frag_offp) { u8 nexthdr = *nexthdrp; + int exthdr_cnt = 0; *frag_offp = 0; @@ -82,6 +83,8 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp, if (nexthdr == NEXTHDR_NONE) return -1; + if (unlikely(exthdr_cnt++ >= IP6_MAX_EXT_HDRS_CNT)) + return -1; hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr); if (!hp) return -1; @@ -190,6 +193,7 @@ 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; + int exthdr_cnt = 0; bool found; if (fragoff) @@ -216,6 +220,9 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, return -ENOENT; } + if (unlikely(exthdr_cnt++ >= IP6_MAX_EXT_HDRS_CNT)) + return -EBADMSG; + hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr); if (!hp) return -EBADMSG; diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index 967b07aeb683..8972863c93ee 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -403,6 +403,7 @@ INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *)); void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr, bool have_final) { + int exthdr_cnt = IP6CB(skb)->flags & IP6SKB_HOPBYHOP ? 1 : 0; const struct inet6_protocol *ipprot; struct inet6_dev *idev; unsigned int nhoff; @@ -487,6 +488,10 @@ resubmit_final: nexthdr = ret; goto resubmit_final; } else { + if (unlikely(exthdr_cnt++ >= IP6_MAX_EXT_HDRS_CNT)) { + SKB_DR_SET(reason, IPV6_TOO_MANY_EXTHDRS); + goto discard; + } goto resubmit; } } else if (ret == 0) { diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index c468c83af0f2..9d1037ac082f 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -399,11 +399,15 @@ __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw) unsigned int nhoff = raw - skb->data; unsigned int off = nhoff + sizeof(*ipv6h); u8 nexthdr = ipv6h->nexthdr; + int exthdr_cnt = 0; while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { struct ipv6_opt_hdr *hdr; u16 optlen; + if (unlikely(exthdr_cnt++ >= IP6_MAX_EXT_HDRS_CNT)) + break; + if (!pskb_may_pull(skb, off + sizeof(*hdr))) break; |