From mboxrd@z Thu Jan 1 00:00:00 1970 From: Emil Goode Date: Wed, 28 May 2014 16:18:39 +0000 Subject: Re: [PATCH] mfd: fix unintentional NULL check in menelaus_set_voltage() Message-Id: <20140528161839.GA16693@lianli> List-Id: References: <1401284030-9650-1-git-send-email-emilgoode@gmail.com> <20140528152011.GB1954@lee--X1> In-Reply-To: <20140528152011.GB1954@lee--X1> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Lee Jones Cc: Samuel Ortiz , Jingoo Han , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Hello, On Wed, May 28, 2014 at 04:20:11PM +0100, Lee Jones wrote: > On Wed, 28 May 2014, Emil Goode wrote: > > > The struct menelaus_vtg pointer vtg cannot be NULL here > > so the condition is never true and if it ever was true > > it would lead to a NULL pointer dereference when we goto > > label set_voltage. > > > > Before the below patch was applied the code was: > > > > if (vtg = 0) > > > > The intention was to check if vtg_val is 0. > > > > commit 59a9f7a32adf6537b4e4db8ca204eeb77d7a634e > > ("mfd: menelaus: Use NULL instead of 0") > > > > Signed-off-by: Emil Goode > > --- > > Hello, > > > > This is only build tested, it would be good to get a comment > > from someone who is familiar with this code. > > > > Found using coccinelle. > > > > Best regards, > > > > Emil Goode > > > > drivers/mfd/menelaus.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/mfd/menelaus.c b/drivers/mfd/menelaus.c > > index ad25bfa..4859597 100644 > > --- a/drivers/mfd/menelaus.c > > +++ b/drivers/mfd/menelaus.c > > @@ -466,7 +466,7 @@ static int menelaus_set_voltage(const struct menelaus_vtg *vtg, int mV, > > struct i2c_client *c = the_menelaus->client; > > > > mutex_lock(&the_menelaus->lock); > > - if (!vtg) > > + if (vtg_val = 0) > > I would prefer: > > if (!vtg_val) Ok, I will resend. Best regards, Emil Goode