[PATCH] USB: fix possible memory leak in pxa27x_udc

[PATCH] USB: fix possible memory leak in pxa27x_udc

[Marcin Slusarz]

Fix memory leak when _ep is null.
http://bugzilla.kernel.org/show_bug.cgi?id=10660

Noticed-by: Daniel Marjamäki <danielm77@spray.se>
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/usb/gadget/pxa27x_udc.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/drivers/usb/gadget/pxa27x_udc.c b/drivers/usb/gadget/pxa27x_udc.c
index e02bfd4..e3a5d53 100644
--- a/drivers/usb/gadget/pxa27x_udc.c
+++ b/drivers/usb/gadget/pxa27x_udc.c
@@ -650,8 +650,11 @@ pxa_ep_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
 {
 	struct pxa27x_request *req;
 
+	if (!_ep)
+		return NULL;
+
 	req = kzalloc(sizeof *req, gfp_flags);
-	if (!req || !_ep)
+	if (!req)
 		return NULL;
 
 	INIT_LIST_HEAD(&req->queue);
-- 
1.5.4.5

Re: [PATCH] USB: fix possible memory leak in pxa27x_udc

[David Brownell]

On Sunday 22 June 2008, Marcin Slusarz wrote:

> --- a/drivers/usb/gadget/pxa27x_udc.c
> +++ b/drivers/usb/gadget/pxa27x_udc.c
> @@ -650,8 +650,11 @@ pxa_ep_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
>  {
>  	struct pxa27x_request *req;
>  
> +	if (!_ep)
> +		return NULL;
> +

Correct enough as it goes, except that it *can't* be null by virtue
of how it's called.  See <include/linux/usb/gadget.h> for:

static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
                                                       gfp_t gfp_flags)
{
        return ep->ops->alloc_request(ep, gfp_flags);
}

If it were null it couldn't get here.  A better fix would just
remove the null check here (and possibly elsewhere).

- Dave


>  	req = kzalloc(sizeof *req, gfp_flags);
> -	if (!req || !_ep)
> +	if (!req)
>  		return NULL;
>  
>  	INIT_LIST_HEAD(&req->queue);
> -- 
> 1.5.4.5
>