[PATCH 6.1 456/473] netfilter: nft_payload: rebuild vlan header when needed

Greg Kroah-Hartman
2024-06-06T14:20:35Z

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit de6843be3082d416eaf2a00b72dad95c784ca980 ]

Skip rebuilding the vlan header when accessing destination and source
mac address.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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 | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index e36627a654244..74777a687eb5f 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -126,7 +126,8 @@ void nft_payload_eval(const struct nft_expr *expr,
if (!skb_mac_header_was_set(skb) || skb_mac_header_len(skb) == 0)
goto err;

- if (skb_vlan_tag_present(skb)) {
+ if (skb_vlan_tag_present(skb) &&
+ priv->offset >= offsetof(struct ethhdr, h_proto)) {
if (!nft_payload_copy_vlan(dest, skb,
priv->offset, priv->len))
goto err;
--
2.43.0