5.10-stable review patch. If anyone has any objections, please let me know.
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From: Phil Sutter phil@nwl.cc
[ Upstream commit 5acc44f39458f43dac9724cefa4da29847cfe997 ]
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@nwl.cc Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 b4682aeabab96..274c5f0085186 100644 --- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -371,6 +371,9 @@ 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) @@ -391,7 +394,7 @@ 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