5.15-stable review patch. If anyone has any objections, please let me know.
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From: Florian Westphal fw@strlen.de
[ Upstream commit af84f9e447a65b4b9f79e7e5d69e19039b431c56 ]
nft can perform merging of adjacent payload requests. This means that:
ether saddr 00:11 ... ether type 8021ad ...
is a single payload expression, for 8 bytes, starting at the ethernet source offset.
Check that offset+length is fully within the source/destination mac addersses.
This bug prevents 'ether type' from matching the correct h_proto in case vlan tag got stripped.
Fixes: de6843be3082 ("netfilter: nft_payload: rebuild vlan header when needed") Reported-by: David Ward david.ward@ll.mit.edu Signed-off-by: Florian Westphal fw@strlen.de Stable-dep-of: 33c563ebf8d3 ("netfilter: nft_payload: skbuff vlan metadata mangle support") Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nft_payload.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index b1745304dbd22..697566e4ae759 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -110,6 +110,17 @@ static int nft_payload_inner_offset(const struct nft_pktinfo *pkt) return pkt->inneroff; }
+static bool nft_payload_need_vlan_copy(const struct nft_payload *priv) +{ + unsigned int len = priv->offset + priv->len; + + /* data past ether src/dst requested, copy needed */ + if (len > offsetof(struct ethhdr, h_proto)) + return true; + + return false; +} + void nft_payload_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) @@ -128,7 +139,7 @@ void nft_payload_eval(const struct nft_expr *expr, goto err;
if (skb_vlan_tag_present(skb) && - priv->offset >= offsetof(struct ethhdr, h_proto)) { + nft_payload_need_vlan_copy(priv)) { if (!nft_payload_copy_vlan(dest, skb, priv->offset, priv->len)) goto err;