Re: [PATCH 2/2] b43legacy: fix unitialized reads of ret by initializing the array to zero

From: Michael BÃsch
Date: Tue Sep 05 2017 - 16:51:06 EST


On Tue, 5 Sep 2017 19:16:58 +0100
Colin King <colin.king@xxxxxxxxxxxxx> wrote:

> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> The u8 char array ret is not being initialized and elements outside
> the range start to end contain just garbage values from the stack.
> This results in a later scan of the array to read potentially
> uninitialized values. Fix this by initializing the array to zero.
> This seems to have been an issue since the very first commit.
>
> Detected by CoverityScan CID#139653 ("Uninitialized scalar variable")
>
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
> drivers/net/wireless/broadcom/b43legacy/radio.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/broadcom/b43legacy/radio.c b/drivers/net/wireless/broadcom/b43legacy/radio.c
> index 9501420340a9..eab1c9387846 100644
> --- a/drivers/net/wireless/broadcom/b43legacy/radio.c
> +++ b/drivers/net/wireless/broadcom/b43legacy/radio.c
> @@ -280,7 +280,7 @@ u8 b43legacy_radio_aci_detect(struct b43legacy_wldev *dev, u8 channel)
> u8 b43legacy_radio_aci_scan(struct b43legacy_wldev *dev)
> {
> struct b43legacy_phy *phy = &dev->phy;
> - u8 ret[13];
> + u8 ret[13] = { 0 };
> unsigned int channel = phy->channel;
> unsigned int i;
> unsigned int j;


This fix seems to be correct.
Thanks for finding and fixing the issue.

Reviewed-by: Michael Buesch <m@xxxxxxx>



--
Michael

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