From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from kirsty.vergenet.net ([202.4.237.240]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1U9BuZ-00025R-PB for kexec@lists.infradead.org; Sat, 23 Feb 2013 10:00:56 +0000 Date: Fri, 22 Feb 2013 15:12:15 -0800 From: Simon Horman Subject: Re: [PATCH] kexec: avoid freeing NULL pointer in function kimage_crash_alloc Message-ID: <20130222231214.GH4737@verge.net.au> References: <5126F92A.2030007@cn.fujitsu.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5126F92A.2030007@cn.fujitsu.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Zhang Yanfei Cc: Andrew Morton , "kexec@lists.infradead.org" , "Eric W. Biederman" , "linux-kernel@vger.kernel.org" On Fri, Feb 22, 2013 at 12:50:50PM +0800, Zhang Yanfei wrote: > Though there is no error if we free a NULL pointer, I think we could > avoid this behaviour. Change the code a little in kimage_crash_alloc() > could avoid this kind of unnecessary free. > > Cc: "Eric W. Biederman" > Cc: Andrew Morton > Signed-off-by: Zhang Yanfei Reviewed-by: Simon Horman > --- > kernel/kexec.c | 15 +++++++-------- > 1 files changed, 7 insertions(+), 8 deletions(-) > > diff --git a/kernel/kexec.c b/kernel/kexec.c > index 5e4bd78..4e96fa7 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -310,7 +310,7 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry, > mend = mstart + image->segment[i].memsz - 1; > /* Ensure we are within the crash kernel limits */ > if ((mstart < crashk_res.start) || (mend > crashk_res.end)) > - goto out; > + goto out_free; > } > > /* > @@ -323,16 +323,15 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry, > get_order(KEXEC_CONTROL_PAGE_SIZE)); > if (!image->control_code_page) { > printk(KERN_ERR "Could not allocate control_code_buffer\n"); > - goto out; > + goto out_free; > } > > - result = 0; > -out: > - if (result == 0) > - *rimage = image; > - else > - kfree(image); > + *rimage = image; > + return 0; > > +out_free: > + kfree(image); > +out: > return result; > } > > -- > 1.7.1 > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec