[PATCH] mt7601u: do not free dma_buf when ivp allocation fails

[Kuba Kicinski]

On 25 February 2016 17:28:59 GMT-05:00, Colin King <colin.king at canonical.com> wrote:
>From: Colin Ian King <colin.king at canonical.com>
>
>If the allocation of ivp fails the error handling attempts to
>free an uninitialized dma_buf; this data structure just contains
>garbage on the stack, so the freeing will cause issues when the
>urb, buf and dma fields are cleaned. Fix this by handling the
>ivp check and

Commit message looks truncated?

>Signed-off-by: Colin Ian King <colin.king at canonical.com>
>---
> drivers/net/wireless/mediatek/mt7601u/mcu.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
>diff --git a/drivers/net/wireless/mediatek/mt7601u/mcu.c
>b/drivers/net/wireless/mediatek/mt7601u/mcu.c
>index fbb1986..06ac657 100644
>--- a/drivers/net/wireless/mediatek/mt7601u/mcu.c
>+++ b/drivers/net/wireless/mediatek/mt7601u/mcu.c
>@@ -359,13 +359,13 @@ mt7601u_upload_firmware(struct mt7601u_dev *dev,
>const struct mt76_fw *fw)
> 	struct mt7601u_dma_buf dma_buf;
> 	void *ivb;
> 	u32 ilm_len, dlm_len;
>-	int i, ret;
>+	int i, ret = -ENOMEM;

No need...

> 
> 	ivb = kmemdup(fw->ivb, sizeof(fw->ivb), GFP_KERNEL);
>-	if (!ivb || mt7601u_usb_alloc_buf(dev, MCU_FW_URB_SIZE, &dma_buf)) {
>-		ret = -ENOMEM;
>+	if (!ivb)
>+		goto error_ivb;

...just return -ENOMEM here, because...

>+error_ivb:
>+	kfree(ivb);

...calling kfree on a null pointer is redundant.

Thanks!!
[trimming To/CC a bit]