Re: [PATCH 5/5] net/netfilter/ipvs: Eliminate memory leak

From: Simon Horman
Date: Tue Aug 24 2010 - 21:34:56 EST


On Tue, Aug 24, 2010 at 04:39:49PM +0200, Julia Lawall wrote:
> From: Julia Lawall <julia@xxxxxxx>
>
> __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/)
>
> // <smpl>
> @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 ...;
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@xxxxxxx>

Thanks Julia, that looks good to me.

Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>

Patrick, I guess that this should go through nf-next-2.6.

>
> ---
> 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..f98169b 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);
>
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