From: Jakub Kicinski <kuba@kernel.org>
Date: Thu, 30 Jan 2025 03:15:18 +0000 (-0800)
Subject: net: ipv6: fix dst refleaks in rpl, seg6 and ioam6 lwtunnels
X-Git-Tag: v5.10.235~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cb9950eaaf9cc76dfe490c06aa11f185b3c7f22b;p=thirdparty%2Fkernel%2Fstable.git

net: ipv6: fix dst refleaks in rpl, seg6 and ioam6 lwtunnels

commit c71a192976ded2f2f416d03c4f595cdd4478b825 upstream.

dst_cache_get() gives us a reference, we need to release it.

Discovered by the ioam6.sh test, kmemleak was recently fixed
to catch per-cpu memory leaks.

Fixes: 985ec6f5e623 ("net: ipv6: rpl_iptunnel: mitigate 2-realloc issue")
Fixes: 40475b63761a ("net: ipv6: seg6_iptunnel: mitigate 2-realloc issue")
Fixes: dce525185bc9 ("net: ipv6: ioam6_iptunnel: mitigate 2-realloc issue")
Reviewed-by: Justin Iurman <justin.iurman@uliege.be>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250130031519.2716843-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c
index 95e84ec035203..5d47948c03642 100644
--- a/net/ipv6/rpl_iptunnel.c
+++ b/net/ipv6/rpl_iptunnel.c
@@ -232,7 +232,6 @@ static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 		dst = ip6_route_output(net, NULL, &fl6);
 		if (dst->error) {
 			err = dst->error;
-			dst_release(dst);
 			goto drop;
 		}
 
@@ -251,6 +250,7 @@ static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 	return dst_output(net, sk, skb);
 
 drop:
+	dst_release(dst);
 	kfree_skb(skb);
 	return err;
 }
@@ -277,8 +277,10 @@ static int rpl_input(struct sk_buff *skb)
 	local_bh_enable();
 
 	err = rpl_do_srh(skb, rlwt, dst);
-	if (unlikely(err))
+	if (unlikely(err)) {
+		dst_release(dst);
 		goto drop;
+	}
 
 	skb_dst_drop(skb);
 
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
index a73840da34ed9..986459a85fbd1 100644
--- a/net/ipv6/seg6_iptunnel.c
+++ b/net/ipv6/seg6_iptunnel.c
@@ -380,7 +380,6 @@ static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 		dst = ip6_route_output(net, NULL, &fl6);
 		if (dst->error) {
 			err = dst->error;
-			dst_release(dst);
 			goto drop;
 		}
 
@@ -398,6 +397,7 @@ static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 
 	return dst_output(net, sk, skb);
 drop:
+	dst_release(dst);
 	kfree_skb(skb);
 	return err;
 }