From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guoqing Jiang Subject: Re: [PATCH] md-cluster: Fix potential error pointer dereference in resize_bitmaps() Date: Tue, 4 Aug 2020 12:40:18 +0200 Message-ID: <824849e0-c98d-1f22-817c-7a76d3ee22b1@cloud.ionos.com> References: <20200804101645.GB392148@mwanda> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200804101645.GB392148@mwanda> Content-Language: en-US Sender: kernel-janitors-owner@vger.kernel.org To: Dan Carpenter , Song Liu Cc: Shaohua Li , NeilBrown , linux-raid@vger.kernel.org, kernel-janitors@vger.kernel.org List-Id: linux-raid.ids On 8/4/20 12:16 PM, Dan Carpenter wrote: > The error handling calls md_bitmap_free(bitmap) which checks for NULL > but will Oops if we pass an error pointer. Let's set "bitmap" to NULL > on this error path. > > Fixes: afd756286083 ("md-cluster/raid10: resize all the bitmaps before start reshape") > Signed-off-by: Dan Carpenter > --- > drivers/md/md-cluster.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c > index 73fd50e77975..d50737ec4039 100644 > --- a/drivers/md/md-cluster.c > +++ b/drivers/md/md-cluster.c > @@ -1139,6 +1139,7 @@ static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsiz > bitmap = get_bitmap_from_slot(mddev, i); > if (IS_ERR(bitmap)) { > pr_err("can't get bitmap from slot %d\n", i); > + bitmap = NULL; > goto out; > } > counts = &bitmap->counts; Thanks for the catch, Reviewed-by: Guoqing Jiang BTW, seems there could be memory leak in the function since it keeps allocate bitmap in the loop ..., will send a format patch. diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c index 73fd50e77975..89d7b32489d8 100644 --- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -1165,6 +1165,8 @@ static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsiz                          * can't resize bitmap                          */                         goto out; + +               md_bitmap_free(bitmap);         }         return 0; Thanks, Guoqing