2017-09-05 18:15:53

by Colin King

[permalink] [raw]
Subject: [PATCH 1/2] b43: fix unitialized reads of ret by initializing the array to zero

From: Colin Ian King <[email protected]>

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#139652 ("Uninitialized scalar variable")

Signed-off-by: Colin Ian King <[email protected]>
---
drivers/net/wireless/broadcom/b43/phy_g.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/b43/phy_g.c b/drivers/net/wireless/broadcom/b43/phy_g.c
index 822dcaa8ace6..f59c02166462 100644
--- a/drivers/net/wireless/broadcom/b43/phy_g.c
+++ b/drivers/net/wireless/broadcom/b43/phy_g.c
@@ -2297,7 +2297,7 @@ static u8 b43_gphy_aci_detect(struct b43_wldev *dev, u8 channel)
static u8 b43_gphy_aci_scan(struct b43_wldev *dev)
{
struct b43_phy *phy = &dev->phy;
- u8 ret[13];
+ u8 ret[13] = { 0 };
unsigned int channel = phy->channel;
unsigned int i, j, start, end;

--
2.14.1


2017-09-20 12:41:25

by Kalle Valo

[permalink] [raw]
Subject: Re: [1/2] b43: fix unitialized reads of ret by initializing the array to zero

Colin Ian King <[email protected]> wrote:

> From: Colin Ian King <[email protected]>
>
> 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#139652 ("Uninitialized scalar variable")
>
> Signed-off-by: Colin Ian King <[email protected]>
> Reviewed-by: Michael Buesch <[email protected]>

2 patches applied to wireless-drivers-next.git, thanks.

e31fbe1034d9 b43: fix unitialized reads of ret by initializing the array to zero
e3ae1c772046 b43legacy: fix unitialized reads of ret by initializing the array to zero

--
https://patchwork.kernel.org/patch/9939435/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

2017-09-05 20:50:46

by Michael Büsch

[permalink] [raw]
Subject: Re: [PATCH 1/2] b43: fix unitialized reads of ret by initializing the array to zero

On Tue, 5 Sep 2017 19:15:50 +0100
Colin King <[email protected]> wrote:

> From: Colin Ian King <[email protected]>
>
> 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#139652 ("Uninitialized scalar variable")
>
> Signed-off-by: Colin Ian King <[email protected]>
> ---
> drivers/net/wireless/broadcom/b43/phy_g.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/broadcom/b43/phy_g.c b/drivers/net/wireless/broadcom/b43/phy_g.c
> index 822dcaa8ace6..f59c02166462 100644
> --- a/drivers/net/wireless/broadcom/b43/phy_g.c
> +++ b/drivers/net/wireless/broadcom/b43/phy_g.c
> @@ -2297,7 +2297,7 @@ static u8 b43_gphy_aci_detect(struct b43_wldev *dev, u8 channel)
> static u8 b43_gphy_aci_scan(struct b43_wldev *dev)
> {
> struct b43_phy *phy = &dev->phy;
> - u8 ret[13];
> + u8 ret[13] = { 0 };
> unsigned int channel = phy->channel;
> unsigned int i, j, start, end;
>


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

Reviewed-by: Michael Buesch <[email protected]>


--
Michael


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