Vivek Kumar Bhagat <vivek.bha...@samsung.com> writes:

> usbnet_start_xmit() - If info->tx_fixup is not defined by class driver,
> NULL check does not happen for skb pointer and leads to NULL dereference.
> __usbnet_read_cmd() - if data pointer is passed as NULL, memcpy will
> dereference NULL pointer.

That's two completely different issues.  Mixing them in a single patch
is only confusing things.


> Signed-off-by: Vivek Kumar Bhagat <vivek.bha...@samsung.com>
> ---
>  drivers/net/usb/usbnet.c |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
> index 3c86b10..ec4d224 100644
> --- a/drivers/net/usb/usbnet.c
> +++ b/drivers/net/usb/usbnet.c
> @@ -1294,6 +1294,8 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
>  
>       if (skb)
>               skb_tx_timestamp(skb);
> +     else
> +             goto drop;
>  
>       // some devices want funky USB-level framing, for
>       // win32 driver (usually) and/or hardware quirks


This is wrong.  There are usbnet minidrivers depending on info->tx_fixup
being called with a NULL skb.


> @@ -1906,7 +1908,8 @@ static int __usbnet_read_cmd(struct usbnet *dev, u8 
> cmd, u8 reqtype,
>               buf = kmalloc(size, GFP_KERNEL);
>               if (!buf)
>                       goto out;
> -     }
> +     } else
> +             goto out;
>  
>       err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
>                             cmd, reqtype, value, index, buf, size,


This is also wrong.  It makes __usbnet_read_cmd() return -ENOMEM if
called with a NULL data pointer.  I don't know if it is used, but it's
perfectly valid to call __usbnet_read_cmd() with data == NULL if
size == 0. No memcpy will happen in this case because usb_control_msg
can only return 0 or an error

Please don't submit any more such patches without proper justification.
You cannot trust that someone will actually take the time to sanity
check your changes.  Patches claiming to fix a NULL dereference should
at least provide an oops.


Bjørn
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to