From c71a192976ded2f2f416d03c4f595cdd4478b825 Mon Sep 17 00:00:00 2001
From: Jakub Kicinski <kuba@kernel.org>
Date: Wed, 29 Jan 2025 19:15:18 -0800
Subject: [PATCH] net: ipv6: fix dst refleaks in rpl, seg6 and ioam6 lwtunnels
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>
---
net/ipv6/ioam6_iptunnel.c | 5 +++--
net/ipv6/rpl_iptunnel.c | 6 ++++--
net/ipv6/seg6_iptunnel.c | 6 ++++--
3 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/ioam6_iptunnel.c b/net/ipv6/ioam6_iptunnel.c
index 28e5a89dc255..3936c137a572 100644
--- a/net/ipv6/ioam6_iptunnel.c
+++ b/net/ipv6/ioam6_iptunnel.c
@@ -336,7 +336,7 @@ static int ioam6_do_encap(struct net *net, struct sk_buff *skb,
static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
- struct dst_entry *dst = skb_dst(skb), *cache_dst;
+ struct dst_entry *dst = skb_dst(skb), *cache_dst = NULL;
struct in6_addr orig_daddr;
struct ioam6_lwt *ilwt;
int err = -EINVAL;
@@ -407,7 +407,6 @@ do_encap:
cache_dst = ip6_route_output(net, NULL, &fl6);
if (cache_dst->error) {
err = cache_dst->error;
- dst_release(cache_dst);
goto drop;
}
@@ -426,8 +425,10 @@ do_encap:
return dst_output(net, sk, skb);
}
out:
+ dst_release(cache_dst);
return dst->lwtstate->orig_output(net, sk, skb);
drop:
+ dst_release(cache_dst);
kfree_skb(skb);
return err;
}
diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c
index 7ba22d2f2bfe..9b7d03563115 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;
}
@@ -269,8 +269,10 @@ 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;
+ }
if (!dst) {
ip6_route_input(skb);
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
index 4bf937bfc263..eacc4e91b48e 100644
--- a/net/ipv6/seg6_iptunnel.c
+++ b/net/ipv6/seg6_iptunnel.c
@@ -482,8 +482,10 @@ static int seg6_input_core(struct net *net, struct sock *sk,
local_bh_enable();
err = seg6_do_srh(skb, dst);
- if (unlikely(err))
+ if (unlikely(err)) {
+ dst_release(dst);
goto drop;
+ }
if (!dst) {
ip6_route_input(skb);
@@ -571,7 +573,6 @@ static int seg6_output_core(struct net *net, struct sock *sk,
dst = ip6_route_output(net, NULL, &fl6);
if (dst->error) {
err = dst->error;
- dst_release(dst);
goto drop;
}
@@ -593,6 +594,7 @@ static int seg6_output_core(struct net *net, struct sock *sk,
return dst_output(net, sk, skb);
drop:
+ dst_release(dst);
kfree_skb(skb);
return err;
}