1 files changed, 49 insertions, 8 deletions

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 1510e951f451..f369e7ce685b 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -249,10 +249,11 @@ bool icmp_global_allow(void)
 	bool rc = false;
 
 	/* Check if token bucket is empty and cannot be refilled
-	 * without taking the spinlock.
+	 * without taking the spinlock. The READ_ONCE() are paired
+	 * with the following WRITE_ONCE() in this same function.
 	 */
-	if (!icmp_global.credit) {
-		delta = min_t(u32, now - icmp_global.stamp, HZ);
+	if (!READ_ONCE(icmp_global.credit)) {
+		delta = min_t(u32, now - READ_ONCE(icmp_global.stamp), HZ);
 		if (delta < HZ / 50)
 			return false;
 	}
@@ -262,14 +263,14 @@ bool icmp_global_allow(void)
 	if (delta >= HZ / 50) {
 		incr = sysctl_icmp_msgs_per_sec * delta / HZ ;
 		if (incr)
-			icmp_global.stamp = now;
+			WRITE_ONCE(icmp_global.stamp, now);
 	}
 	credit = min_t(u32, icmp_global.credit + incr, sysctl_icmp_msgs_burst);
 	if (credit) {
 		credit--;
 		rc = true;
 	}
-	icmp_global.credit = credit;
+	WRITE_ONCE(icmp_global.credit, credit);
 	spin_unlock(&icmp_global.lock);
 	return rc;
 }
@@ -582,7 +583,13 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info,
 
 	if (!rt)
 		goto out;
-	net = dev_net(rt->dst.dev);
+
+	if (rt->dst.dev)
+		net = dev_net(rt->dst.dev);
+	else if (skb_in->dev)
+		net = dev_net(skb_in->dev);
+	else
+		goto out;
 
 	/*
 	 *	Find the original header. It is expected to be valid, of course.
@@ -676,7 +683,8 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info,
 			dev = dev_get_by_index_rcu(net, inet_iif(skb_in));
 
 		if (dev)
-			saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK);
+			saddr = inet_select_addr(dev, iph->saddr,
+						 RT_SCOPE_LINK);
 		else
 			saddr = 0;
 		rcu_read_unlock();
@@ -740,6 +748,39 @@ out:;
 }
 EXPORT_SYMBOL(__icmp_send);
 
+#if IS_ENABLED(CONFIG_NF_NAT)
+#include <net/netfilter/nf_conntrack.h>
+void icmp_ndo_send(struct sk_buff *skb_in, int type, int code, __be32 info)
+{
+	struct sk_buff *cloned_skb = NULL;
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+	__be32 orig_ip;
+
+	ct = nf_ct_get(skb_in, &ctinfo);
+	if (!ct || !(ct->status & IPS_SRC_NAT)) {
+		icmp_send(skb_in, type, code, info);
+		return;
+	}
+
+	if (skb_shared(skb_in))
+		skb_in = cloned_skb = skb_clone(skb_in, GFP_ATOMIC);
+
+	if (unlikely(!skb_in || skb_network_header(skb_in) < skb_in->head ||
+	    (skb_network_header(skb_in) + sizeof(struct iphdr)) >
+	    skb_tail_pointer(skb_in) || skb_ensure_writable(skb_in,
+	    skb_network_offset(skb_in) + sizeof(struct iphdr))))
+		goto out;
+
+	orig_ip = ip_hdr(skb_in)->saddr;
+	ip_hdr(skb_in)->saddr = ct->tuplehash[0].tuple.src.u3.ip;
+	icmp_send(skb_in, type, code, info);
+	ip_hdr(skb_in)->saddr = orig_ip;
+out:
+	consume_skb(cloned_skb);
+}
+EXPORT_SYMBOL(icmp_ndo_send);
+#endif
 
 static void icmp_socket_deliver(struct sk_buff *skb, u32 info)
 {
@@ -902,7 +943,7 @@ static bool icmp_redirect(struct sk_buff *skb)
 		return false;
 	}
 
-	icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway);
+	icmp_socket_deliver(skb, ntohl(icmp_hdr(skb)->un.gateway));
 	return true;
 }