From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Date: Sat, 05 Jun 2010 06:50:02 +0000 Subject: Re: [patch] input: off by one in pcf8574_kp_irq_handler() Message-Id: <20100605085002.064a6888@hyperion.delvare> List-Id: References: <20100604231939.GJ5483@bicker> In-Reply-To: <20100604231939.GJ5483@bicker> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Carpenter Cc: Dmitry Torokhov , Mike Frysinger , Greg Kroah-Hartman , Richard Purdie , linux-input@vger.kernel.org, kernel-janitors@vger.kernel.org Hi Dan, On Sat, 5 Jun 2010 01:19:39 +0200, Dan Carpenter wrote: > If nextstate = ARRAY_SIZE(lp->btncode), then we read one past the end of > the array on the next line. > > This fixes a smatch warning: > drivers/input/misc/pcf8574_keypad.c +74 pcf8574_kp_irq_handler(8) > error: buffer overflow 'lp->btncode' 17 <= 17 > > Signed-off-by: Dan Carpenter > > diff --git a/drivers/input/misc/pcf8574_keypad.c b/drivers/input/misc/pcf8574_keypad.c > index 0ac47d2..4b42ffc 100644 > --- a/drivers/input/misc/pcf8574_keypad.c > +++ b/drivers/input/misc/pcf8574_keypad.c > @@ -69,7 +69,7 @@ static irqreturn_t pcf8574_kp_irq_handler(int irq, void *dev_id) > unsigned char nextstate = read_state(lp); > > if (lp->laststate != nextstate) { > - int key_down = nextstate <= ARRAY_SIZE(lp->btncode); > + int key_down = nextstate < ARRAY_SIZE(lp->btncode); > unsigned short keycode = key_down ? > lp->btncode[nextstate] : lp->btncode[lp->laststate]; > Good catch. Acked-by: Jean Delvare -- Jean Delvare