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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Wim Van Sebroeck <wim@iguana.be>
Cc: linux-watchdog@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [patch] watchdog: w83977f_wdt: underflow in wdt_set_timeout()
Date: Fri, 6 Nov 2015 12:56:31 +0300	[thread overview]
Message-ID: <20151106095631.GA18557@mwanda> (raw)

"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.

             reply	other threads:[~2015-11-06  9:56 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-06  9:56 Dan Carpenter [this message]
2015-11-06 13:58 ` [patch] watchdog: w83977f_wdt: underflow in wdt_set_timeout() Guenter Roeck

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