Aug 24 2010

net/netfilter/ipvs: Eliminate memory leak 

Author: Julia Lawall <julia@diku.dk>

__ip_vs_service_get and __ip_vs_svc_fwm_get increment a reference count, so
that reference count should be decremented before leaving the function in an
error case.

A simplified version of the semantic match that finds this problem is:
(http://coccinelle.lip6.fr/)

// 
@r exists@
local idexpression x;
expression E;
identifier f1;
iterator I;
@@

x = __ip_vs_service_get(...);
<... when != x
     when != true (x == NULL || ...)
     when != if (...) { <+...x...+> }
     when != I (...) { <+...x...+> }
(
 x == NULL
|
 x == E
|
 x->f1
)
...>
* return ...;
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Simon Horman 
Signed-off-by: David S. Miller 

---
 net/netfilter/ipvs/ip_vs_ctl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
 
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 0f0c079..53a88af 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -2155,7 +2155,7 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
 	if (cmd != IP_VS_SO_SET_ADD
 	    && (svc == NULL || svc->protocol != usvc.protocol)) {
 		ret = -ESRCH;
-		goto out_unlock;
+		goto out_drop_service;
 	}
 
 	switch (cmd) {
@@ -2189,6 +2189,7 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
 		ret = -EINVAL;
 	}
 
+out_drop_service:
 	if (svc)
 		ip_vs_service_put(svc);

qlambert