[PATCH] staging: rtl8192e: rtllib_module: Fix memory leak in alloc_rtllib

[PATCH] staging: rtl8192e: rtllib_module: Fix memory leak in alloc_rtllib

[Navid Emamdoost]

In the implementation of alloc_rtllib() the allocated dev is leaked in
case of ieee->pHTInfo allocation failure. Release via free_netdev(dev).

Fixes: 6869a11bff1d ("Staging: rtl8192e: Use !x instead of x == NULL")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
---
 drivers/staging/rtl8192e/rtllib_module.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8192e/rtllib_module.c b/drivers/staging/rtl8192e/rtllib_module.c
index 64d9feee1f39..18d898714c5c 100644
--- a/drivers/staging/rtl8192e/rtllib_module.c
+++ b/drivers/staging/rtl8192e/rtllib_module.c
@@ -125,7 +125,7 @@ struct net_device *alloc_rtllib(int sizeof_priv)
 
 	ieee->pHTInfo = kzalloc(sizeof(struct rt_hi_throughput), GFP_KERNEL);
 	if (!ieee->pHTInfo)
-		return NULL;
+		goto failed;
 
 	HTUpdateDefaultSetting(ieee);
 	HTInitializeHTInfo(ieee);
-- 
2.17.1

Re: [PATCH] staging: rtl8192e: rtllib_module: Fix memory leak in alloc_rtllib

[Johan Hovold]

On Sat, Dec 14, 2019 at 05:05:58PM -0600, Navid Emamdoost wrote:
> In the implementation of alloc_rtllib() the allocated dev is leaked in
> case of ieee->pHTInfo allocation failure. Release via free_netdev(dev).
> 
> Fixes: 6869a11bff1d ("Staging: rtl8192e: Use !x instead of x == NULL")

This is not the commit that introduced this issue.

> Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> ---
>  drivers/staging/rtl8192e/rtllib_module.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/rtl8192e/rtllib_module.c b/drivers/staging/rtl8192e/rtllib_module.c
> index 64d9feee1f39..18d898714c5c 100644
> --- a/drivers/staging/rtl8192e/rtllib_module.c
> +++ b/drivers/staging/rtl8192e/rtllib_module.c
> @@ -125,7 +125,7 @@ struct net_device *alloc_rtllib(int sizeof_priv)
>  
>  	ieee->pHTInfo = kzalloc(sizeof(struct rt_hi_throughput), GFP_KERNEL);
>  	if (!ieee->pHTInfo)
> -		return NULL;
> +		goto failed;

And you're still leaking ieee->networks and possibly a bunch of other
allocations here. You need to call at least rtllib_networks_free() in
the error path.

>  
>  	HTUpdateDefaultSetting(ieee);
>  	HTInitializeHTInfo(ieee);

Johan

Re: [PATCH] staging: rtl8192e: rtllib_module: Fix memory leak in alloc_rtllib

[Navid Emamdoost]

Hi Johan,

On Sun, Dec 15, 2019 at 7:23 AM Johan Hovold <johan@kernel.org> wrote:
>
> On Sat, Dec 14, 2019 at 05:05:58PM -0600, Navid Emamdoost wrote:
> > In the implementation of alloc_rtllib() the allocated dev is leaked in
> > case of ieee->pHTInfo allocation failure. Release via free_netdev(dev).
> >
> > Fixes: 6869a11bff1d ("Staging: rtl8192e: Use !x instead of x == NULL")
>
> This is not the commit that introduced this issue.
Oops! That should be  94a799425eee8

>
> > Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> > ---
> >  drivers/staging/rtl8192e/rtllib_module.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/staging/rtl8192e/rtllib_module.c b/drivers/staging/rtl8192e/rtllib_module.c
> > index 64d9feee1f39..18d898714c5c 100644
> > --- a/drivers/staging/rtl8192e/rtllib_module.c
> > +++ b/drivers/staging/rtl8192e/rtllib_module.c
> > @@ -125,7 +125,7 @@ struct net_device *alloc_rtllib(int sizeof_priv)
> >
> >       ieee->pHTInfo = kzalloc(sizeof(struct rt_hi_throughput), GFP_KERNEL);
> >       if (!ieee->pHTInfo)
> > -             return NULL;
> > +             goto failed;
>
> And you're still leaking ieee->networks and possibly a bunch of other
> allocations here. You need to call at least rtllib_networks_free() in
> the error path.
I'm not familiar with this code, but based on your hint I believe
there should be something like free_rtllib() here, right?
More specifically, rtllib_softmac_free() and
lib80211_crypt_info_free() are needed along with
rtllib_networks_free(). If you confirm that it works I can go ahead to
prepare patch v2 with these releases.

>
> >
> >       HTUpdateDefaultSetting(ieee);
> >       HTInitializeHTInfo(ieee);
>
> Johan



-- 
Navid.

Re: [PATCH] staging: rtl8192e: rtllib_module: Fix memory leak in alloc_rtllib

[Johan Hovold]

On Sun, Dec 15, 2019 at 08:42:47PM -0600, Navid Emamdoost wrote:
> Hi Johan,
> 
> On Sun, Dec 15, 2019 at 7:23 AM Johan Hovold <johan@kernel.org> wrote:
> >
> > On Sat, Dec 14, 2019 at 05:05:58PM -0600, Navid Emamdoost wrote:
> > > In the implementation of alloc_rtllib() the allocated dev is leaked in
> > > case of ieee->pHTInfo allocation failure. Release via free_netdev(dev).
> > >
> > > Fixes: 6869a11bff1d ("Staging: rtl8192e: Use !x instead of x == NULL")
> >
> > This is not the commit that introduced this issue.
> Oops! That should be  94a799425eee8
> 
> >
> > > Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> > > ---
> > >  drivers/staging/rtl8192e/rtllib_module.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/staging/rtl8192e/rtllib_module.c b/drivers/staging/rtl8192e/rtllib_module.c
> > > index 64d9feee1f39..18d898714c5c 100644
> > > --- a/drivers/staging/rtl8192e/rtllib_module.c
> > > +++ b/drivers/staging/rtl8192e/rtllib_module.c
> > > @@ -125,7 +125,7 @@ struct net_device *alloc_rtllib(int sizeof_priv)
> > >
> > >       ieee->pHTInfo = kzalloc(sizeof(struct rt_hi_throughput), GFP_KERNEL);
> > >       if (!ieee->pHTInfo)
> > > -             return NULL;
> > > +             goto failed;
> >
> > And you're still leaking ieee->networks and possibly a bunch of other
> > allocations here. You need to call at least rtllib_networks_free() in
> > the error path.
> I'm not familiar with this code, but based on your hint I believe
> there should be something like free_rtllib() here, right?

Right.

> More specifically, rtllib_softmac_free() and
> lib80211_crypt_info_free() are needed along with
> rtllib_networks_free(). If you confirm that it works I can go ahead to
> prepare patch v2 with these releases.

I can't confirm anything, that's your job. ;)

You need to trace the calls and allocations made in in alloc_rtllib()
and make sure everything is released on errors. For a well-designed
subsystem and driver this should end up looking a lot like the release
function (free_rtllib()), but that's unfortunately not always the case.

Judging from a quick look at least rtllib_softmac_free() is also needed
besides rtllib_networks_free(). And you probably want
lib80211_crypt_info_free() as well for consistency even if the
corresponding init functions doesn't seem to do any allocations
currently.

Johan