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* [patch] watchdog: w83977f_wdt: underflow in wdt_set_timeout()
@ 2015-11-06  9:56 Dan Carpenter
  2015-11-06 13:58 ` Guenter Roeck
  0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2015-11-06  9:56 UTC (permalink / raw)
  To: Wim Van Sebroeck; +Cc: linux-watchdog, kernel-janitors

"t" is controlled by the user.  If "t" is a very large integer then it
could lead to a negative "tmrval".  We cap the upper bound of "tmrval"
but, in the current code, we allow negatives.  This is a bug and it
causes a static checker warning.  Let's make "tmrval" unsigned to avoid
this problem.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/watchdog/w83977f_wdt.c b/drivers/watchdog/w83977f_wdt.c
index 91bf55a..20e2bba 100644
--- a/drivers/watchdog/w83977f_wdt.c
+++ b/drivers/watchdog/w83977f_wdt.c
@@ -224,7 +224,7 @@ static int wdt_keepalive(void)
 
 static int wdt_set_timeout(int t)
 {
-	int tmrval;
+	unsigned int tmrval;
 
 	/*
 	 * Convert seconds to watchdog counter time units, rounding up.

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [patch] watchdog: w83977f_wdt: underflow in wdt_set_timeout()
  2015-11-06  9:56 [patch] watchdog: w83977f_wdt: underflow in wdt_set_timeout() Dan Carpenter
@ 2015-11-06 13:58 ` Guenter Roeck
  0 siblings, 0 replies; 2+ messages in thread
From: Guenter Roeck @ 2015-11-06 13:58 UTC (permalink / raw)
  To: Dan Carpenter, Wim Van Sebroeck; +Cc: linux-watchdog, kernel-janitors

On 11/06/2015 01:56 AM, Dan Carpenter wrote:
> "t" is controlled by the user.  If "t" is a very large integer then it
> could lead to a negative "tmrval".  We cap the upper bound of "tmrval"
> but, in the current code, we allow negatives.  This is a bug and it
> causes a static checker warning.  Let's make "tmrval" unsigned to avoid
> this problem.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> diff --git a/drivers/watchdog/w83977f_wdt.c b/drivers/watchdog/w83977f_wdt.c
> index 91bf55a..20e2bba 100644
> --- a/drivers/watchdog/w83977f_wdt.c
> +++ b/drivers/watchdog/w83977f_wdt.c
> @@ -224,7 +224,7 @@ static int wdt_keepalive(void)
>
>   static int wdt_set_timeout(int t)
>   {
> -	int tmrval;
> +	unsigned int tmrval;
>
>   	/*
>   	 * Convert seconds to watchdog counter time units, rounding up.
> --
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^ permalink raw reply	[flat|nested] 2+ messages in thread

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2015-11-06  9:56 [patch] watchdog: w83977f_wdt: underflow in wdt_set_timeout() Dan Carpenter
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