[PATCH] Fix for possible null pointer dereference in keyspan.c

[PATCH] Fix for possible null pointer dereference in keyspan.c

[Rickard Strandqvist]

There is otherwise a risk of a possible null pointer dereference.

Was largely found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
---
 drivers/usb/serial/keyspan.c |    4 ++--
 1 fil ändrad, 2 tillägg(+), 2 borttagningar(-)

diff --git a/drivers/usb/serial/keyspan.c b/drivers/usb/serial/keyspan.c
index d3acaea..93cb7ce 100644
--- a/drivers/usb/serial/keyspan.c
+++ b/drivers/usb/serial/keyspan.c
@@ -1535,14 +1535,14 @@ static int keyspan_usa26_send_setup(struct usb_serial *serial,
 
 	this_urb = p_priv->outcont_urb;
 
-	dev_dbg(&port->dev, "%s - endpoint %d\n", __func__, usb_pipeendpoint(this_urb->pipe));
-
 		/* Make sure we have an urb then send the message */
 	if (this_urb == NULL) {
 		dev_dbg(&port->dev, "%s - oops no urb.\n", __func__);
 		return -1;
 	}
 
+	dev_dbg(&port->dev, "%s - endpoint %d\n", __func__, usb_pipeendpoint(this_urb->pipe));
+
 	/* Save reset port val for resend.
 	   Don't overwrite resend for open/close condition. */
 	if ((reset_port + 1) > p_priv->resend_cont)
-- 
1.7.10.4

Re: [PATCH] Fix for possible null pointer dereference in keyspan.c

[Johan Hovold]

On Thu, May 15, 2014 at 11:55:10PM +0200, Rickard Strandqvist wrote:
> There is otherwise a risk of a possible null pointer dereference.

I don't think this can be triggered unless the URB allocation fails at
probe, but let's move the offending line nonetheless.

I'll fix up the patch subject as well.

> Was largely found by using a static code analysis program called cppcheck.
> 
> Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
> ---
>  drivers/usb/serial/keyspan.c |    4 ++--
>  1 fil ändrad, 2 tillägg(+), 2 borttagningar(-)

Diff stats in Swedish?! :)

Thanks,
Johan

> diff --git a/drivers/usb/serial/keyspan.c b/drivers/usb/serial/keyspan.c
> index d3acaea..93cb7ce 100644
> --- a/drivers/usb/serial/keyspan.c
> +++ b/drivers/usb/serial/keyspan.c
> @@ -1535,14 +1535,14 @@ static int keyspan_usa26_send_setup(struct usb_serial *serial,
>  
>  	this_urb = p_priv->outcont_urb;
>  
> -	dev_dbg(&port->dev, "%s - endpoint %d\n", __func__, usb_pipeendpoint(this_urb->pipe));
> -
>  		/* Make sure we have an urb then send the message */
>  	if (this_urb == NULL) {
>  		dev_dbg(&port->dev, "%s - oops no urb.\n", __func__);
>  		return -1;
>  	}
>  
> +	dev_dbg(&port->dev, "%s - endpoint %d\n", __func__, usb_pipeendpoint(this_urb->pipe));
> +
>  	/* Save reset port val for resend.
>  	   Don't overwrite resend for open/close condition. */
>  	if ((reset_port + 1) > p_priv->resend_cont)

[PATCH] USB: keyspan: fix potential null pointer dereference

[Johan Hovold]

From: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>

Move control-urb dereference to after NULL-check. There is otherwise a
risk of a possible null pointer dereference.

Was largely found by using a static code analysis program called
cppcheck.

[Johan: modify commit message somewhat ]

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Cc: stable <stable@vger.kernel.org>	# v2.6.12
Signed-off-by: Johan Hovold <jhovold@gmail.com>
---
 drivers/usb/serial/keyspan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/serial/keyspan.c b/drivers/usb/serial/keyspan.c
index d3acaead5a81..93cb7cebda62 100644
--- a/drivers/usb/serial/keyspan.c
+++ b/drivers/usb/serial/keyspan.c
@@ -1535,14 +1535,14 @@ static int keyspan_usa26_send_setup(struct usb_serial *serial,
 
 	this_urb = p_priv->outcont_urb;
 
-	dev_dbg(&port->dev, "%s - endpoint %d\n", __func__, usb_pipeendpoint(this_urb->pipe));
-
 		/* Make sure we have an urb then send the message */
 	if (this_urb == NULL) {
 		dev_dbg(&port->dev, "%s - oops no urb.\n", __func__);
 		return -1;
 	}
 
+	dev_dbg(&port->dev, "%s - endpoint %d\n", __func__, usb_pipeendpoint(this_urb->pipe));
+
 	/* Save reset port val for resend.
 	   Don't overwrite resend for open/close condition. */
 	if ((reset_port + 1) > p_priv->resend_cont)
-- 
1.8.5.5