From: Xin Long Date: Mon, 18 Mar 2019 11:47:00 +0000 (+0800) Subject: sctp: get sctphdr by offset in sctp_compute_cksum X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=273160ffc6b993c7c91627f5a84799c66dfe4dee;p=openwrt%2Fstaging%2Fblogic.git sctp: get sctphdr by offset in sctp_compute_cksum sctp_hdr(skb) only works when skb->transport_header is set properly. But in Netfilter, skb->transport_header for ipv6 is not guaranteed to be right value for sctphdr. It would cause to fail to check the checksum for sctp packets. So fix it by using offset, which is always right in all places. v1->v2: - Fix the changelog. Fixes: e6d8b64b34aa ("net: sctp: fix and consolidate SCTP checksumming code") Reported-by: Li Shuang Signed-off-by: Xin Long Signed-off-by: David S. Miller --- diff --git a/include/net/sctp/checksum.h b/include/net/sctp/checksum.h index 32ee65a30aff..1c6e6c0766ca 100644 --- a/include/net/sctp/checksum.h +++ b/include/net/sctp/checksum.h @@ -61,7 +61,7 @@ static inline __wsum sctp_csum_combine(__wsum csum, __wsum csum2, static inline __le32 sctp_compute_cksum(const struct sk_buff *skb, unsigned int offset) { - struct sctphdr *sh = sctp_hdr(skb); + struct sctphdr *sh = (struct sctphdr *)(skb->data + offset); const struct skb_checksum_ops ops = { .update = sctp_csum_update, .combine = sctp_csum_combine,