Xin Long <lucien.xin@xxxxxxxxx> writes:
> br_nf_check_hbh_len() is a function to check the Hop-by-hop option
> header, and shouldn't do pskb_trim_rcsum() there. This patch is to
> pass pkt_len out to br_validate_ipv6() and do pskb_trim_rcsum()
> after calling br_validate_ipv6() instead.
>
> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
> ---
Reviewed-by: Aaron Conole <aconole@xxxxxxxxxx>
> net/bridge/br_netfilter_ipv6.c | 33 ++++++++++++++-------------------
> 1 file changed, 14 insertions(+), 19 deletions(-)
>
> diff --git a/net/bridge/br_netfilter_ipv6.c b/net/bridge/br_netfilter_ipv6.c
> index 50f564c33551..07289e4f3213 100644
> --- a/net/bridge/br_netfilter_ipv6.c
> +++ b/net/bridge/br_netfilter_ipv6.c
> @@ -43,11 +43,11 @@
> /* We only check the length. A bridge shouldn't do any hop-by-hop stuff
> * anyway
> */
> -static int br_nf_check_hbh_len(struct sk_buff *skb)
> +static int br_nf_check_hbh_len(struct sk_buff *skb, u32 *plen)
> {
> int len, off = sizeof(struct ipv6hdr);
> unsigned char *nh;
> - u32 pkt_len;
> + u32 pkt_len = 0;
>
> if (!pskb_may_pull(skb, off + 8))
> return -1;
> @@ -83,10 +83,6 @@ static int br_nf_check_hbh_len(struct sk_buff *skb)
> return -1;
> if (pkt_len > skb->len - sizeof(struct ipv6hdr))
> return -1;
> - if (pskb_trim_rcsum(skb,
> - pkt_len + sizeof(struct ipv6hdr)))
> - return -1;
> - nh = skb_network_header(skb);
> }
> off += optlen;
> len -= optlen;
> @@ -94,6 +90,8 @@ static int br_nf_check_hbh_len(struct sk_buff *skb)
> if (len)
> return -1;
>
> + if (pkt_len)
> + *plen = pkt_len;
> return 0;
> }
>
> @@ -116,22 +114,19 @@ int br_validate_ipv6(struct net *net, struct sk_buff *skb)
> goto inhdr_error;
>
> pkt_len = ntohs(hdr->payload_len);
> + if (hdr->nexthdr == NEXTHDR_HOP && br_nf_check_hbh_len(skb, &pkt_len))
> + goto drop;
>
> - if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
> - if (pkt_len + ip6h_len > skb->len) {
> - __IP6_INC_STATS(net, idev,
> - IPSTATS_MIB_INTRUNCATEDPKTS);
> - goto drop;
> - }
> - if (pskb_trim_rcsum(skb, pkt_len + ip6h_len)) {
> - __IP6_INC_STATS(net, idev,
> - IPSTATS_MIB_INDISCARDS);
> - goto drop;
> - }
> - hdr = ipv6_hdr(skb);
> + if (pkt_len + ip6h_len > skb->len) {
> + __IP6_INC_STATS(net, idev,
> + IPSTATS_MIB_INTRUNCATEDPKTS);
> + goto drop;
> }
> - if (hdr->nexthdr == NEXTHDR_HOP && br_nf_check_hbh_len(skb))
> + if (pskb_trim_rcsum(skb, pkt_len + ip6h_len)) {
> + __IP6_INC_STATS(net, idev,
> + IPSTATS_MIB_INDISCARDS);
> goto drop;
> + }
>
> memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
> /* No IP options in IPv6 header; however it should be
