Merge tag 'nf-24-08-22' 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 disable BH when collecting stats via hardware offload to ensure concurrent updates from packet path do not result in losing stats. From Sebastian Andrzej Siewior. Patch #2 uses write seqcount to reset counters serialize against reader. Also from Sebastian Andrzej Siewior. Patch #3 ensures vlan header is in place before accessing its fields, according to KMSAN splat triggered by syzbot. * tag 'nf-24-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: flowtable: validate vlan header netfilter: nft_counter: Synchronize nft_counter_reset() against reader. netfilter: nft_counter: Disable BH in nft_counter_offload_stats(). ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
akiyks · Aug 22, 2024 · 3ddbf7b · 3ddbf7b
2 parents 2696c15 + 6ea14cc
commit 3ddbf7b
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Showing 3 changed files with 13 additions and 2 deletions.
diff --git a/net/netfilter/nf_flow_table_inet.c b/net/netfilter/nf_flow_table_inet.c
@@ -17,6 +17,9 @@ nf_flow_offload_inet_hook(void *priv, struct sk_buff *skb,
 
 	switch (skb->protocol) {
 	case htons(ETH_P_8021Q):
+		if (!pskb_may_pull(skb, skb_mac_offset(skb) + sizeof(*veth)))
+			return NF_ACCEPT;
+
 		veth = (struct vlan_ethhdr *)skb_mac_header(skb);
 		proto = veth->h_vlan_encapsulated_proto;
 		break;

diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
@@ -281,6 +281,9 @@ static bool nf_flow_skb_encap_protocol(struct sk_buff *skb, __be16 proto,
 
 	switch (skb->protocol) {
 	case htons(ETH_P_8021Q):
+		if (!pskb_may_pull(skb, skb_mac_offset(skb) + sizeof(*veth)))
+			return false;
+
 		veth = (struct vlan_ethhdr *)skb_mac_header(skb);
 		if (veth->h_vlan_encapsulated_proto == proto) {
 			*offset += VLAN_HLEN;

diff --git a/net/netfilter/nft_counter.c b/net/netfilter/nft_counter.c
@@ -107,11 +107,16 @@ static void nft_counter_reset(struct nft_counter_percpu_priv *priv,
 			      struct nft_counter *total)
 {
 	struct nft_counter *this_cpu;
+	seqcount_t *myseq;
 
 	local_bh_disable();
 	this_cpu = this_cpu_ptr(priv->counter);
+	myseq = this_cpu_ptr(&nft_counter_seq);
+
+	write_seqcount_begin(myseq);
 	this_cpu->packets -= total->packets;
 	this_cpu->bytes -= total->bytes;
+	write_seqcount_end(myseq);
 	local_bh_enable();
 }
 
@@ -265,15 +270,15 @@ static void nft_counter_offload_stats(struct nft_expr *expr,
 	struct nft_counter *this_cpu;
 	seqcount_t *myseq;
 
-	preempt_disable();
+	local_bh_disable();
 	this_cpu = this_cpu_ptr(priv->counter);
 	myseq = this_cpu_ptr(&nft_counter_seq);
 
 	write_seqcount_begin(myseq);
 	this_cpu->packets += stats->pkts;
 	this_cpu->bytes += stats->bytes;
 	write_seqcount_end(myseq);
-	preempt_enable();
+	local_bh_enable();
 }
 
 void nft_counter_init_seqcount(void)