2020-09-02 11:10:57

by Nicolas Boichat

Subject: [PATCH v2] rpmsg: Avoid double-free in mtk_rpmsg_register_device

If rpmsg_register_device fails, it will call
mtk_rpmsg_release_device which already frees mdev.

Fixes: 7017996951fde84 ("rpmsg: add rpmsg support for mt8183 SCP.")
Signed-off-by: Nicolas Boichat <[email protected]>
---

Changes in v2:
- Drop useless if and ret variable (Markus Elfring)

drivers/rpmsg/mtk_rpmsg.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/rpmsg/mtk_rpmsg.c b/drivers/rpmsg/mtk_rpmsg.c
index 83f2b8804ee989d..96a17ec2914011d 100644
--- a/drivers/rpmsg/mtk_rpmsg.c
+++ b/drivers/rpmsg/mtk_rpmsg.c
@@ -200,7 +200,6 @@ static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev,
struct rpmsg_device *rpdev;
struct mtk_rpmsg_device *mdev;
struct platform_device *pdev = mtk_subdev->pdev;
- int ret;

mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
if (!mdev)
@@ -219,13 +218,7 @@ static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev,
rpdev->dev.parent = &pdev->dev;
rpdev->dev.release = mtk_rpmsg_release_device;

- ret = rpmsg_register_device(rpdev);
- if (ret) {
- kfree(mdev);
- return ret;
- }
-
- return 0;
+ return rpmsg_register_device(rpdev);
}

static void mtk_register_device_work_function(struct work_struct *register_work)
--
2.28.0.402.g5ffc5be6b7-goog

2020-09-02 16:58:41

by Mathieu Poirier

Subject: Re: [PATCH v2] rpmsg: Avoid double-free in mtk_rpmsg_register_device

On Wed, Sep 02, 2020 at 07:07:15PM +0800, Nicolas Boichat wrote:
> If rpmsg_register_device fails, it will call
> mtk_rpmsg_release_device which already frees mdev.
>
> Fixes: 7017996951fde84 ("rpmsg: add rpmsg support for mt8183 SCP.")

The SHA should be 12 characters instead of 15. With that:

Reviewed-by: Mathieu Poirier <[email protected]>

> Signed-off-by: Nicolas Boichat <[email protected]>
> ---
>
> Changes in v2:
> - Drop useless if and ret variable (Markus Elfring)
>
> drivers/rpmsg/mtk_rpmsg.c | 9 +--------
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/drivers/rpmsg/mtk_rpmsg.c b/drivers/rpmsg/mtk_rpmsg.c
> index 83f2b8804ee989d..96a17ec2914011d 100644
> --- a/drivers/rpmsg/mtk_rpmsg.c
> +++ b/drivers/rpmsg/mtk_rpmsg.c
> @@ -200,7 +200,6 @@ static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev,
> struct rpmsg_device *rpdev;
> struct mtk_rpmsg_device *mdev;
> struct platform_device *pdev = mtk_subdev->pdev;
> - int ret;
>
> mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
> if (!mdev)
> @@ -219,13 +218,7 @@ static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev,
> rpdev->dev.parent = &pdev->dev;
> rpdev->dev.release = mtk_rpmsg_release_device;
>
> - ret = rpmsg_register_device(rpdev);
> - if (ret) {
> - kfree(mdev);
> - return ret;
> - }
> -
> - return 0;
> + return rpmsg_register_device(rpdev);
> }
>
> static void mtk_register_device_work_function(struct work_struct *register_work)
> --
> 2.28.0.402.g5ffc5be6b7-goog
>

2020-09-03 00:09:15

by Nicolas Boichat

Subject: Re: [PATCH v2] rpmsg: Avoid double-free in mtk_rpmsg_register_device

On Thu, Sep 3, 2020 at 12:55 AM Mathieu Poirier
<[email protected]> wrote:
>
> On Wed, Sep 02, 2020 at 07:07:15PM +0800, Nicolas Boichat wrote:
> > If rpmsg_register_device fails, it will call
> > mtk_rpmsg_release_device which already frees mdev.
> >
> > Fixes: 7017996951fde84 ("rpmsg: add rpmsg support for mt8183 SCP.")
>
> The SHA should be 12 characters instead of 15. With that:

Done in v3, thanks (and fixed my process for next time).

> Reviewed-by: Mathieu Poirier <[email protected]>
>
> > Signed-off-by: Nicolas Boichat <[email protected]>
> > ---
> >
> > Changes in v2:
> > - Drop useless if and ret variable (Markus Elfring)
> >
> > drivers/rpmsg/mtk_rpmsg.c | 9 +--------
> > 1 file changed, 1 insertion(+), 8 deletions(-)
> >
> > diff --git a/drivers/rpmsg/mtk_rpmsg.c b/drivers/rpmsg/mtk_rpmsg.c
> > index 83f2b8804ee989d..96a17ec2914011d 100644
> > --- a/drivers/rpmsg/mtk_rpmsg.c
> > +++ b/drivers/rpmsg/mtk_rpmsg.c
> > @@ -200,7 +200,6 @@ static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev,
> > struct rpmsg_device *rpdev;
> > struct mtk_rpmsg_device *mdev;
> > struct platform_device *pdev = mtk_subdev->pdev;
> > - int ret;
> >
> > mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
> > if (!mdev)
> > @@ -219,13 +218,7 @@ static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev,
> > rpdev->dev.parent = &pdev->dev;
> > rpdev->dev.release = mtk_rpmsg_release_device;
> >
> > - ret = rpmsg_register_device(rpdev);
> > - if (ret) {
> > - kfree(mdev);
> > - return ret;
> > - }
> > -
> > - return 0;
> > + return rpmsg_register_device(rpdev);
> > }
> >
> > static void mtk_register_device_work_function(struct work_struct *register_work)
> > --
> > 2.28.0.402.g5ffc5be6b7-goog
> >