[IPV6]: Fix potential net leak and oops in ipv6 routing code.

The commits f3db4851 ([NETNS][IPV6] ip6_fib - fib6_clean_all handle several 
network namespaces) and 69ddb805 ([NETNS][IPV6] route6 - Make proc entry 
/proc/net/rt6_stats per namespace) made some proc files per net.

Both of them introduced potential OOPS - get_proc_net can return NULL, but
this check is lost - and a struct net leak - in case single_open() fails the
previously got net is not put.

Kill all these bugs with one patch.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 2 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index ac4428371432..cd82b6db35ff 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2390,10 +2390,18 @@ static int ipv6_route_show(struct seq_file *m, void *v)
 
 static int ipv6_route_open(struct inode *inode, struct file *file)
 {
+        int err;
         struct net *net = get_proc_net(inode);
         if (!net)
                 return -ENXIO;
-        return single_open(file, ipv6_route_show, net);
+
+        err = single_open(file, ipv6_route_show, net);
+        if (err < 0) {
+                put_net(net);
+                return err;
+        }
+
+        return 0;
 }
 
 static int ipv6_route_release(struct inode *inode, struct file *file)
@@ -2429,8 +2437,18 @@ static int rt6_stats_seq_show(struct seq_file *seq, void *v)
 
 static int rt6_stats_seq_open(struct inode *inode, struct file *file)
 {
+        int err;
         struct net *net = get_proc_net(inode);
-        return single_open(file, rt6_stats_seq_show, net);
+        if (!net)
+                return -ENXIO;
+
+        err = single_open(file, rt6_stats_seq_show, net);
+        if (err < 0) {
+                put_net(net);
+                return err;
+        }
+
+        return 0;
 }
 
 static int rt6_stats_seq_release(struct inode *inode, struct file *file)