[PATCH] wil6210: increase cmd buffer size to avoid sscanf buffer overflow

[PATCH] wil6210: increase cmd buffer size to avoid sscanf buffer overflow

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

cppcheck detected a buffer overflow:

[drivers/net/wireless/ath/wil6210/debugfs.c:634]: (error) Width 8
  given in format string (no. 1) is larger than destination buffer
  'cmd[8]', use %7s to prevent overflowing it.

For the current %8s sscanf we require cmd to be 9 chars long
so increase it by 1 byte to prevent the sscan overflow (rather
than reduce the %8s specifier to %7s as cppcheck recommends).

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/wireless/ath/wil6210/debugfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c
index 45c3558e..29aab12 100644
--- a/drivers/net/wireless/ath/wil6210/debugfs.c
+++ b/drivers/net/wireless/ath/wil6210/debugfs.c
@@ -618,7 +618,7 @@ static ssize_t wil_write_back(struct file *file, const char __user *buf,
 	struct wil6210_priv *wil = file->private_data;
 	int rc;
 	char *kbuf = kmalloc(len + 1, GFP_KERNEL);
-	char cmd[8];
+	char cmd[9];
 	int p1, p2, p3;
 
 	if (!kbuf)
-- 
2.1.4

Re: [PATCH] wil6210: increase cmd buffer size to avoid sscanf buffer overflow

[Vladimir Kondratiev]

On 03/01/2015 07:48 PM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> cppcheck detected a buffer overflow:
>
> [drivers/net/wireless/ath/wil6210/debugfs.c:634]: (error) Width 8
>    given in format string (no. 1) is larger than destination buffer
>    'cmd[8]', use %7s to prevent overflowing it.
>
> For the current %8s sscanf we require cmd to be 9 chars long
> so increase it by 1 byte to prevent the sscan overflow (rather
> than reduce the %8s specifier to %7s as cppcheck recommends).
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   drivers/net/wireless/ath/wil6210/debugfs.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c
> index 45c3558e..29aab12 100644
> --- a/drivers/net/wireless/ath/wil6210/debugfs.c
> +++ b/drivers/net/wireless/ath/wil6210/debugfs.c
> @@ -618,7 +618,7 @@ static ssize_t wil_write_back(struct file *file, const char __user *buf,
>   	struct wil6210_priv *wil = file->private_data;
>   	int rc;
>   	char *kbuf = kmalloc(len + 1, GFP_KERNEL);
> -	char cmd[8];
> +	char cmd[9];
>   	int p1, p2, p3;
>
>   	if (!kbuf)
>
Thanks for finding this. Here is my
Acked-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>

Thanks, Vladimir

Re: wil6210: increase cmd buffer size to avoid sscanf buffer overflow

[Kalle Valo]

> From: Colin Ian King <colin.king@canonical.com>
> 
> cppcheck detected a buffer overflow:
> 
> [drivers/net/wireless/ath/wil6210/debugfs.c:634]: (error) Width 8
>   given in format string (no. 1) is larger than destination buffer
>   'cmd[8]', use %7s to prevent overflowing it.
> 
> For the current %8s sscanf we require cmd to be 9 chars long
> so increase it by 1 byte to prevent the sscan overflow (rather
> than reduce the %8s specifier to %7s as cppcheck recommends).
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> Acked-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>

Thanks, applied to wireless-drivers-next.git.

Kalle Valo