netdev - [PATCH net 3/6] netfilter: nft_payload: restore vlan q-in-q match support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240522231355.9802-4-pablo@netfilter.org>
Date: Thu, 23 May 2024 01:13:52 +0200
From: Pablo Neira Ayuso <pablo@...filter.org>
To: netfilter-devel@...r.kernel.org
Cc: davem@...emloft.net,
	netdev@...r.kernel.org,
	kuba@...nel.org,
	pabeni@...hat.com,
	edumazet@...gle.com,
	fw@...len.de
Subject: [PATCH net 3/6] netfilter: nft_payload: restore vlan q-in-q match support

Revert f6ae9f120dad ("netfilter: nft_payload: add C-VLAN support").

f41f72d09ee1 ("netfilter: nft_payload: simplify vlan header handling")
already allows to match on inner vlan tags by subtract the vlan header
size to the payload offset which has been popped and stored in skbuff
metadata fields.

Fixes: f6ae9f120dad ("netfilter: nft_payload: add C-VLAN support")
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/netfilter/nft_payload.c | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index 0a689c8e0295..a3cb5dbcb362 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -45,36 +45,27 @@ nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len)
 	int mac_off = skb_mac_header(skb) - skb->data;
 	u8 *vlanh, *dst_u8 = (u8 *) d;
 	struct vlan_ethhdr veth;
-	u8 vlan_hlen = 0;
-
-	if ((skb->protocol == htons(ETH_P_8021AD) ||
-	     skb->protocol == htons(ETH_P_8021Q)) &&
-	    offset >= VLAN_ETH_HLEN && offset < VLAN_ETH_HLEN + VLAN_HLEN)
-		vlan_hlen += VLAN_HLEN;
 
 	vlanh = (u8 *) &veth;
-	if (offset < VLAN_ETH_HLEN + vlan_hlen) {
+	if (offset < VLAN_ETH_HLEN) {
 		u8 ethlen = len;
 
-		if (vlan_hlen &&
-		    skb_copy_bits(skb, mac_off, &veth, VLAN_ETH_HLEN) < 0)
-			return false;
-		else if (!nft_payload_rebuild_vlan_hdr(skb, mac_off, &veth))
+		if (!nft_payload_rebuild_vlan_hdr(skb, mac_off, &veth))
 			return false;
 
-		if (offset + len > VLAN_ETH_HLEN + vlan_hlen)
-			ethlen -= offset + len - VLAN_ETH_HLEN - vlan_hlen;
+		if (offset + len > VLAN_ETH_HLEN)
+			ethlen -= offset + len - VLAN_ETH_HLEN;
 
-		memcpy(dst_u8, vlanh + offset - vlan_hlen, ethlen);
+		memcpy(dst_u8, vlanh + offset, ethlen);
 
 		len -= ethlen;
 		if (len == 0)
 			return true;
 
 		dst_u8 += ethlen;
-		offset = ETH_HLEN + vlan_hlen;
+		offset = ETH_HLEN;
 	} else {
-		offset -= VLAN_HLEN + vlan_hlen;
+		offset -= VLAN_HLEN;
 	}
 
 	return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0;
-- 
2.30.2