net: avoid use IPCB in cipso_v4_error

Extract IP options in cipso_v4_error and use __icmp_send. Signed-off-by: Sergey Nazarov <s-nazarov@yandex.ru> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net>
nemunaire · Feb 25, 2019 · 3da1ed7 · 3da1ed7
1 parent 9ef6b42
commit 3da1ed7
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Showing 3 changed files with 34 additions and 7 deletions.
diff --git a/include/net/ip.h b/include/net/ip.h
@@ -667,6 +667,8 @@ static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
 }
 
 void ip_options_fragment(struct sk_buff *skb);
+int __ip_options_compile(struct net *net, struct ip_options *opt,
+			 struct sk_buff *skb, __be32 *info);
 int ip_options_compile(struct net *net, struct ip_options *opt,
 		       struct sk_buff *skb);
 int ip_options_get(struct net *net, struct ip_options_rcu **optp,

diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
@@ -1735,13 +1735,26 @@ int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
  */
 void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
 {
+	unsigned char optbuf[sizeof(struct ip_options) + 40];
+	struct ip_options *opt = (struct ip_options *)optbuf;
+
 	if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
 		return;
 
+	/*
+	 * We might be called above the IP layer,
+	 * so we can not use icmp_send and IPCB here.
+	 */
+
+	memset(opt, 0, sizeof(struct ip_options));
+	opt->optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr);
+	if (__ip_options_compile(dev_net(skb->dev), opt, skb, NULL))
+		return;
+
 	if (gateway)
-		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0);
+		__icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, opt);
 	else
-		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0);
+		__icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, opt);
 }
 
 /**

diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
@@ -251,8 +251,9 @@ static void spec_dst_fill(__be32 *spec_dst, struct sk_buff *skb)
  * If opt == NULL, then skb->data should point to IP header.
  */
 
-int ip_options_compile(struct net *net,
-		       struct ip_options *opt, struct sk_buff *skb)
+int __ip_options_compile(struct net *net,
+			 struct ip_options *opt, struct sk_buff *skb,
+			 __be32 *info)
 {
 	__be32 spec_dst = htonl(INADDR_ANY);
 	unsigned char *pp_ptr = NULL;
@@ -468,11 +469,22 @@ int ip_options_compile(struct net *net,
 		return 0;
 
 error:
-	if (skb) {
-		icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));
-	}
+	if (info)
+		*info = htonl((pp_ptr-iph)<<24);
 	return -EINVAL;
 }
+
+int ip_options_compile(struct net *net,
+		       struct ip_options *opt, struct sk_buff *skb)
+{
+	int ret;
+	__be32 info;
+
+	ret = __ip_options_compile(net, opt, skb, &info);
+	if (ret != 0 && skb)
+		icmp_send(skb, ICMP_PARAMETERPROB, 0, info);
+	return ret;
+}
 EXPORT_SYMBOL(ip_options_compile);
 
 /*