[PATCH] drm/msm: Fix possible uninitialized access in fbdev

[PATCH] drm/msm: Fix possible uninitialized access in fbdev

[Thomas Zimmermann]

Do not run drm_fb_helper_unprepare() if fbdev allocation fails. Avoids
access to an uninitialized pointer. Original bug report is at [1].

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 3fb1f62f80a1 ("drm/fb-helper: Remove drm_fb_helper_unprepare() from drm_fb_helper_fini()")
Link: https://lore.kernel.org/oe-kbuild-all/202302220810.9dymwCQ8-lkp@intel.com/ # 1
---
 drivers/gpu/drm/msm/msm_fbdev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_fbdev.c b/drivers/gpu/drm/msm/msm_fbdev.c
index c804e5ba682a..d26aa52217ce 100644
--- a/drivers/gpu/drm/msm/msm_fbdev.c
+++ b/drivers/gpu/drm/msm/msm_fbdev.c
@@ -136,13 +136,13 @@ static const struct drm_fb_helper_funcs msm_fb_helper_funcs = {
 struct drm_fb_helper *msm_fbdev_init(struct drm_device *dev)
 {
 	struct msm_drm_private *priv = dev->dev_private;
-	struct msm_fbdev *fbdev = NULL;
+	struct msm_fbdev *fbdev;
 	struct drm_fb_helper *helper;
 	int ret;
 
 	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
 	if (!fbdev)
-		goto fail;
+		return NULL;
 
 	helper = &fbdev->base;
 
-- 
2.39.2

Re: [PATCH] drm/msm: Fix possible uninitialized access in fbdev

[Dmitry Baryshkov]

On 22/02/2023 14:37, Thomas Zimmermann wrote:
> Do not run drm_fb_helper_unprepare() if fbdev allocation fails. Avoids
> access to an uninitialized pointer. Original bug report is at [1].
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: 3fb1f62f80a1 ("drm/fb-helper: Remove drm_fb_helper_unprepare() from drm_fb_helper_fini()")
> Link: https://lore.kernel.org/oe-kbuild-all/202302220810.9dymwCQ8-lkp@intel.com/ # 1
> ---
>   drivers/gpu/drm/msm/msm_fbdev.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

-- 
With best wishes
Dmitry

Re: [PATCH] drm/msm: Fix possible uninitialized access in fbdev

[Thomas Zimmermann]

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Hi

Am 22.02.23 um 13:37 schrieb Dmitry Baryshkov:
> On 22/02/2023 14:37, Thomas Zimmermann wrote:
>> Do not run drm_fb_helper_unprepare() if fbdev allocation fails. Avoids
>> access to an uninitialized pointer. Original bug report is at [1].
>>
>> Reported-by: kernel test robot <lkp@intel.com>
>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>> Fixes: 3fb1f62f80a1 ("drm/fb-helper: Remove drm_fb_helper_unprepare() 
>> from drm_fb_helper_fini()")
>> Link: 
>> https://lore.kernel.org/oe-kbuild-all/202302220810.9dymwCQ8-lkp@intel.com/ # 1
>> ---
>>   drivers/gpu/drm/msm/msm_fbdev.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> 

Impressive response time. Thanks a lot.

Best regards
Thomas

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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Re: [PATCH] drm/msm: Fix possible uninitialized access in fbdev

[Abhinav Kumar]

On 2/22/2023 4:37 AM, Thomas Zimmermann wrote:
> Do not run drm_fb_helper_unprepare() if fbdev allocation fails. Avoids
> access to an uninitialized pointer. Original bug report is at [1].
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: 3fb1f62f80a1 ("drm/fb-helper: Remove drm_fb_helper_unprepare() from drm_fb_helper_fini()")
> Link: https://lore.kernel.org/oe-kbuild-all/202302220810.9dymwCQ8-lkp@intel.com/ # 1
> ---
>   drivers/gpu/drm/msm/msm_fbdev.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>