On Fri, Jun 15, 2018 at 10:28 AM, Zhouyang Jia <jiazhouyang09@xxxxxxxxx> wrote:
> When usb_alloc_urb fails, the lack of error-handling code may
> cause unexpected results.
>
> This patch adds error-handling code after calling usb_alloc_urb.
>
> Signed-off-by: Zhouyang Jia <jiazhouyang09@xxxxxxxxx>
> ---
> v1->v2:
> - Fix memory leak.
> v2->v3:
> - Release memory in error path.
> ---
> drivers/staging/rtl8192u/r8192U_core.c | 24 +++++++++++++++---------
> 1 file changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/staging/rtl8192u/r8192U_core.c b/drivers/staging/rtl8192u/r8192U_core.c
> index 7a0dbc0..1c980e9 100644
> --- a/drivers/staging/rtl8192u/r8192U_core.c
> +++ b/drivers/staging/rtl8192u/r8192U_core.c
> @@ -1649,12 +1649,12 @@ static short rtl8192_usb_initendpoints(struct net_device *dev)
> for (i = 0; i < (MAX_RX_URB + 1); i++) {
> priv->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
> if (!priv->rx_urb[i])
> - return -ENOMEM;
> + goto out_release_mem;
You need to use kcalloc() above here for priv->rx_urb, otherwise you
may free random garbage. :)
-Kees
>
> priv->rx_urb[i]->transfer_buffer =
> kmalloc(RX_URB_SIZE, GFP_KERNEL);
> if (!priv->rx_urb[i]->transfer_buffer)
> - return -ENOMEM;
> + goto out_release_mem;
>
> priv->rx_urb[i]->transfer_buffer_length = RX_URB_SIZE;
> }
> @@ -1666,9 +1666,13 @@ static short rtl8192_usb_initendpoints(struct net_device *dev)
> void *oldaddr, *newaddr;
>
> priv->rx_urb[16] = usb_alloc_urb(0, GFP_KERNEL);
> + if (!priv->rx_urb[16])
> + goto out_release_mem;
> +
> priv->oldaddr = kmalloc(16, GFP_KERNEL);
> if (!priv->oldaddr)
> - return -ENOMEM;
> + goto out_release_mem;
> +
> oldaddr = priv->oldaddr;
> align = ((long)oldaddr) & 3;
> if (align) {
> @@ -1686,17 +1690,19 @@ static short rtl8192_usb_initendpoints(struct net_device *dev)
> priv->pp_rxskb = kcalloc(MAX_RX_URB, sizeof(struct sk_buff *),
> GFP_KERNEL);
> if (!priv->pp_rxskb) {
> - kfree(priv->rx_urb);
> -
> - priv->pp_rxskb = NULL;
> - priv->rx_urb = NULL;
> -
> DMESGE("Endpoint Alloc Failure");
> - return -ENOMEM;
> + goto out_release_mem;
> }
>
> netdev_dbg(dev, "End of initendpoints\n");
> return 0;
> +
> +out_release_mem:
> + for (i = 0; i < (MAX_RX_URB + 1); i++)
> + kfree(priv->rx_urb[i]);
> + kfree(priv->rx_urb);
> + priv->rx_urb = NULL;
> + return -ENOMEM;
> }
>
> #ifdef THOMAS_BEACON
> --
> 2.7.4
>
--
Kees Cook
Pixel Security
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