[PATCH net-next] lwtunnel: fix memory leak

[PATCH net-next] lwtunnel: fix memory leak

[Jiri Benc]

The built lwtunnel_state struct has to be freed after comparison.

Fixes: 571e722676fe3 ("ipv4: support for fib route lwtunnel encap attributes")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
---
 include/net/lwtunnel.h   |  7 ++++++-
 net/ipv4/fib_semantics.c | 10 ++++++----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h
index e25b60eb262d..34fd8f70c2ca 100644
--- a/include/net/lwtunnel.h
+++ b/include/net/lwtunnel.h
@@ -36,6 +36,11 @@ struct lwtunnel_encap_ops {
 };
 
 #ifdef CONFIG_LWTUNNEL
+static inline void lwtstate_free(struct lwtunnel_state *lws)
+{
+	kfree(lws);
+}
+
 static inline struct lwtunnel_state *
 lwtstate_get(struct lwtunnel_state *lws)
 {
@@ -51,7 +56,7 @@ static inline void lwtstate_put(struct lwtunnel_state *lws)
 		return;
 
 	if (atomic_dec_and_test(&lws->refcnt))
-		kfree(lws);
+		lwtstate_free(lws);
 }
 
 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index c8025851dac7..d5253071f71f 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -539,7 +539,7 @@ int fib_encap_match(struct net *net, u16 encap_type,
 {
 	struct lwtunnel_state *lwtstate;
 	struct net_device *dev = NULL;
-	int ret;
+	int ret, result = 0;
 
 	if (encap_type == LWTUNNEL_ENCAP_NONE)
 		return 0;
@@ -548,10 +548,12 @@ int fib_encap_match(struct net *net, u16 encap_type,
 		dev = __dev_get_by_index(net, oif);
 	ret = lwtunnel_build_state(dev, encap_type,
 				   encap, &lwtstate);
-	if (!ret)
-		return lwtunnel_cmp_encap(lwtstate, nh->nh_lwtstate);
+	if (!ret) {
+		result = lwtunnel_cmp_encap(lwtstate, nh->nh_lwtstate);
+		lwtstate_free(lwtstate);
+	}
 
-	return 0;
+	return result;
 }
 
 int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)
-- 
1.8.3.1

[PATCH net-next] lwtunnel: ip tunnel: fix multiple routes with different encap

[Jiri Benc]

Currently, two routes going through the same tunnel interface are considered
the same even when they are routed to a different host after encapsulation.
This causes all routes added after the first one to have incorrect
encapsulation parameters.

This is nicely visible by doing:

  # ip r a 192.168.1.2/32 dev vxlan0 tunnel dst 10.0.0.2
  # ip r a 192.168.1.3/32 dev vxlan0 tunnel dst 10.0.0.3
  # ip r
  [...]
  192.168.1.2/32 tunnel id 0 src 0.0.0.0 dst 10.0.0.2 [...]
  192.168.1.3/32 tunnel id 0 src 0.0.0.0 dst 10.0.0.2 [...]

Implement the missing comparison function.

Fixes: 3093fbe7ff4bc ("route: Per route IP tunnel metadata via lightweight tunnel")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
---
 net/ipv4/ip_tunnel_core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index fd6319681c50..1c2389d582a6 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -286,10 +286,17 @@ static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
 		+ nla_total_size(2);	/* LWTUNNEL_IP_FLAGS */
 }
 
+static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
+{
+	return memcmp(lwt_tun_info(a), lwt_tun_info(b),
+		      sizeof(struct ip_tunnel_info));
+}
+
 static const struct lwtunnel_encap_ops ip_tun_lwt_ops = {
 	.build_state = ip_tun_build_state,
 	.fill_encap = ip_tun_fill_encap_info,
 	.get_encap_size = ip_tun_encap_nlsize,
+	.cmp_encap = ip_tun_cmp_encap,
 };
 
 void __init ip_tunnel_core_init(void)
-- 
1.8.3.1

Re: [PATCH net-next] lwtunnel: fix memory leak

[roopa]

On 8/18/15, 9:41 AM, Jiri Benc wrote:
> The built lwtunnel_state struct has to be freed after comparison.
>
> Fixes: 571e722676fe3 ("ipv4: support for fib route lwtunnel encap attributes")
> Signed-off-by: Jiri Benc <jbenc@redhat.com>
> ---
>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>

looks like this was introduced in my last version when i decided to drop 
the get/put of lwtstate here. Thanks!

Re: [PATCH net-next] lwtunnel: fix memory leak

[David Miller]

From: Jiri Benc <jbenc@redhat.com>
Date: Tue, 18 Aug 2015 18:41:13 +0200

> The built lwtunnel_state struct has to be freed after comparison.
> 
> Fixes: 571e722676fe3 ("ipv4: support for fib route lwtunnel encap attributes")
> Signed-off-by: Jiri Benc <jbenc@redhat.com>

Applied.

Re: [PATCH net-next] lwtunnel: ip tunnel: fix multiple routes with different encap

[David Miller]

From: Jiri Benc <jbenc@redhat.com>
Date: Tue, 18 Aug 2015 18:42:09 +0200

> Currently, two routes going through the same tunnel interface are considered
> the same even when they are routed to a different host after encapsulation.
> This causes all routes added after the first one to have incorrect
> encapsulation parameters.
> 
> This is nicely visible by doing:
> 
>   # ip r a 192.168.1.2/32 dev vxlan0 tunnel dst 10.0.0.2
>   # ip r a 192.168.1.3/32 dev vxlan0 tunnel dst 10.0.0.3
>   # ip r
>   [...]
>   192.168.1.2/32 tunnel id 0 src 0.0.0.0 dst 10.0.0.2 [...]
>   192.168.1.3/32 tunnel id 0 src 0.0.0.0 dst 10.0.0.2 [...]
> 
> Implement the missing comparison function.
> 
> Fixes: 3093fbe7ff4bc ("route: Per route IP tunnel metadata via lightweight tunnel")
> Signed-off-by: Jiri Benc <jbenc@redhat.com>

Applied.