Merge tag 'nf-24-08-28' of git://git.kernel.org/pub/scm/linux/kernel/…

…git/netfilter/nf Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for net: Patch #1 sets on NFT_PKTINFO_L4PROTO for UDP packets less than 4 bytes payload from netdev/egress by subtracting skb_network_offset() when validating IPv4 packet length, otherwise 'meta l4proto udp' never matches. Patch #2 subtracts skb_network_offset() when validating IPv6 packet length for netdev/egress. netfilter pull request 24-08-28 * tag 'nf-24-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: nf_tables_ipv6: consider network offset in netdev/egress validation netfilter: nf_tables: restore IP sanity checks for netdev/egress ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Paolo Abeni <[email protected]>
thesofproject · Aug 29, 2024 · 0240bce · 0240bce
2 parents 6213dcc + 70c261d
commit 0240bce
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Showing 2 changed files with 9 additions and 6 deletions.
diff --git a/include/net/netfilter/nf_tables_ipv4.h b/include/net/netfilter/nf_tables_ipv4.h
@@ -19,7 +19,7 @@ static inline void nft_set_pktinfo_ipv4(struct nft_pktinfo *pkt)
 static inline int __nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt)
 {
 	struct iphdr *iph, _iph;
-	u32 len, thoff;
+	u32 len, thoff, skb_len;
 
 	iph = skb_header_pointer(pkt->skb, skb_network_offset(pkt->skb),
 				 sizeof(*iph), &_iph);
@@ -30,8 +30,10 @@ static inline int __nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt)
 		return -1;
 
 	len = iph_totlen(pkt->skb, iph);
-	thoff = skb_network_offset(pkt->skb) + (iph->ihl * 4);
-	if (pkt->skb->len < len)
+	thoff = iph->ihl * 4;
+	skb_len = pkt->skb->len - skb_network_offset(pkt->skb);
+
+	if (skb_len < len)
 		return -1;
 	else if (len < thoff)
 		return -1;
@@ -40,7 +42,7 @@ static inline int __nft_set_pktinfo_ipv4_validate(struct nft_pktinfo *pkt)
 
 	pkt->flags = NFT_PKTINFO_L4PROTO;
 	pkt->tprot = iph->protocol;
-	pkt->thoff = thoff;
+	pkt->thoff = skb_network_offset(pkt->skb) + thoff;
 	pkt->fragoff = ntohs(iph->frag_off) & IP_OFFSET;
 
 	return 0;

diff --git a/include/net/netfilter/nf_tables_ipv6.h b/include/net/netfilter/nf_tables_ipv6.h
@@ -31,8 +31,8 @@ static inline int __nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt)
 	struct ipv6hdr *ip6h, _ip6h;
 	unsigned int thoff = 0;
 	unsigned short frag_off;
+	u32 pkt_len, skb_len;
 	int protohdr;
-	u32 pkt_len;
 
 	ip6h = skb_header_pointer(pkt->skb, skb_network_offset(pkt->skb),
 				  sizeof(*ip6h), &_ip6h);
@@ -43,7 +43,8 @@ static inline int __nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt)
 		return -1;
 
 	pkt_len = ntohs(ip6h->payload_len);
-	if (pkt_len + sizeof(*ip6h) > pkt->skb->len)
+	skb_len = pkt->skb->len - skb_network_offset(pkt->skb);
+	if (pkt_len + sizeof(*ip6h) > skb_len)
 		return -1;
 
 	protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, &flags);