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

[Colin King]

From: Colin Ian King <***@canonical.com>

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 <***@canonical.com>
---
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;

[Michael Büsch]

On Tue, 5 Sep 2017 19:16:58 +0100

Post by Colin King
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")
---
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 <***@bues.ch>