From: Dan Williams <dan.j.williams@intel.com>
To: Kangjie Lu <kjlu@umn.edu>
Cc: linux-nvdimm <linux-nvdimm@lists.01.org>,
pakki001@umn.edu,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Ross Zwisler <zwisler@kernel.org>
Subject: Re: [PATCH] nvdimm: btt_devs: fix a NULL pointer dereference and a memory leak
Date: Fri, 22 Mar 2019 15:55:10 -0700 [thread overview]
Message-ID: <CAPcyv4jfoUCK8dCCgGRG3GPxxk2mgrQd=zpJ9OnwzngXJ+LwpA@mail.gmail.com> (raw)
In-Reply-To: <20190312081529.4889-1-kjlu@umn.edu>
On Tue, Mar 12, 2019 at 1:16 AM Kangjie Lu <kjlu@umn.edu> wrote:
>
> In case kmemdup fails, the fix releases resources and returns to
> avoid the NULL pointer dereference.
> Also, the error paths in the following code should release
> resources to avoid memory leaks.
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
> drivers/nvdimm/btt_devs.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
> index 795ad4ff35ca..565ea0b6f765 100644
> --- a/drivers/nvdimm/btt_devs.c
> +++ b/drivers/nvdimm/btt_devs.c
> @@ -196,8 +196,13 @@ static struct device *__nd_btt_create(struct nd_region *nd_region,
> }
>
> nd_btt->lbasize = lbasize;
> - if (uuid)
> + if (uuid) {
> uuid = kmemdup(uuid, 16, GFP_KERNEL);
> + if (!uuid) {
> + kfree(nd_btt);
> + return NULL;
What about nd_btt->id? That needs to be released as well.
> + }
> + }
> nd_btt->uuid = uuid;
> dev = &nd_btt->dev;
> dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
> @@ -209,6 +214,7 @@ static struct device *__nd_btt_create(struct nd_region *nd_region,
> dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
> dev_name(ndns->claim));
> put_device(dev);
> + kfree(uuid);
This will be a double free because put_device() will arrange for
nd_btt_release() to be called which does kfree(nd_btt->uuid);
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prev parent reply other threads:[~2019-03-22 22:55 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-12 8:15 [PATCH] nvdimm: btt_devs: fix a NULL pointer dereference and a memory leak Kangjie Lu
2019-03-22 22:49 ` Verma, Vishal L
2019-03-22 22:56 ` Verma, Vishal L
2019-03-22 23:31 ` Verma, Vishal L
2019-03-22 22:55 ` Dan Williams [this message]
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