From: Phil Sutter <phil@xxxxxx>
Since user space does not generate a payload dependency, plain sctp
chunk matches cause searching in non-SCTP packets, too. Avoid this
potential mis-interpretation of packet data by checking pkt->tprot.
Fixes: 133dc203d77df ("netfilter: nft_exthdr: Support SCTP chunks")
Signed-off-by: Phil Sutter <phil@xxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nft_exthdr.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c
index 7f705b5c09de..9cf86be2cff4 100644
--- a/net/netfilter/nft_exthdr.c
+++ b/net/netfilter/nft_exthdr.c
@@ -312,6 +312,9 @@ static void nft_exthdr_sctp_eval(const struct nft_expr *expr,
const struct sctp_chunkhdr *sch;
struct sctp_chunkhdr _sch;
+ if (pkt->tprot != IPPROTO_SCTP)
+ goto err;
+
do {
sch = skb_header_pointer(pkt->skb, offset, sizeof(_sch), &_sch);
if (!sch || !sch->length)
@@ -334,7 +337,7 @@ static void nft_exthdr_sctp_eval(const struct nft_expr *expr,
}
offset += SCTP_PAD4(ntohs(sch->length));
} while (offset < pkt->skb->len);
-
+err:
if (priv->flags & NFT_EXTHDR_F_PRESENT)
nft_reg_store8(dest, false);
else
--
2.30.2
