[PATCH] drm/bridge-connector: Fix double free in error handling paths

[PATCH] drm/bridge-connector: Fix double free in error handling paths

[Cristian Ciocaltea]

The recent switch to drmm allocation in drm_bridge_connector_init() may
cause double free on bridge_connector in some of the error handling
paths.

Drop the explicit kfree() calls on bridge_connector.

Fixes: c12907be57b1 ("drm/bridge-connector: switch to using drmm allocations")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/drm_bridge_connector.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_bridge_connector.c b/drivers/gpu/drm/drm_bridge_connector.c
index 0869b663f17e..a4fbf1eb7ac5 100644
--- a/drivers/gpu/drm/drm_bridge_connector.c
+++ b/drivers/gpu/drm/drm_bridge_connector.c
@@ -443,10 +443,8 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
 			panel_bridge = bridge;
 	}
 
-	if (connector_type == DRM_MODE_CONNECTOR_Unknown) {
-		kfree(bridge_connector);
+	if (connector_type == DRM_MODE_CONNECTOR_Unknown)
 		return ERR_PTR(-EINVAL);
-	}
 
 	if (bridge_connector->bridge_hdmi)
 		ret = drmm_connector_hdmi_init(drm, connector,
@@ -461,10 +459,8 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
 		ret = drmm_connector_init(drm, connector,
 					  &drm_bridge_connector_funcs,
 					  connector_type, ddc);
-	if (ret) {
-		kfree(bridge_connector);
+	if (ret)
 		return ERR_PTR(ret);
-	}
 
 	drm_connector_helper_add(connector, &drm_bridge_connector_helper_funcs);
 

---
base-commit: 1eb586a9782cde8e5091b9de74603e0a8386b09e
change-id: 20240711-bridge-connector-fix-dbl-free-9dd324f0b270

Re: [PATCH] drm/bridge-connector: Fix double free in error handling paths

[Dmitry Baryshkov]

On Thu, Jul 11, 2024 at 02:26:55PM GMT, Cristian Ciocaltea wrote:
> The recent switch to drmm allocation in drm_bridge_connector_init() may
> cause double free on bridge_connector in some of the error handling
> paths.
> 
> Drop the explicit kfree() calls on bridge_connector.
> 
> Fixes: c12907be57b1 ("drm/bridge-connector: switch to using drmm allocations")
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
> ---
>  drivers/gpu/drm/drm_bridge_connector.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 

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


-- 
With best wishes
Dmitry

Re: [PATCH] drm/bridge-connector: Fix double free in error handling paths

[Robert Foss]

On Thu, 11 Jul 2024 14:26:55 +0300, Cristian Ciocaltea wrote:
> The recent switch to drmm allocation in drm_bridge_connector_init() may
> cause double free on bridge_connector in some of the error handling
> paths.
> 
> Drop the explicit kfree() calls on bridge_connector.
> 
> 
> [...]

Applied, thanks!

[1/1] drm/bridge-connector: Fix double free in error handling paths
      https://cgit.freedesktop.org/drm/drm-misc/commit/?id=ca5442ed8f53



Rob

Re: [PATCH] drm/bridge-connector: Fix double free in error handling paths

[Cristian Ciocaltea]

Hi Robert,

On 7/18/24 3:02 PM, Robert Foss wrote:
> On Thu, 11 Jul 2024 14:26:55 +0300, Cristian Ciocaltea wrote:
>> The recent switch to drmm allocation in drm_bridge_connector_init() may
>> cause double free on bridge_connector in some of the error handling
>> paths.
>>
>> Drop the explicit kfree() calls on bridge_connector.
>>
>>
>> [...]
> 
> Applied, thanks!
> 
> [1/1] drm/bridge-connector: Fix double free in error handling paths
>       https://cgit.freedesktop.org/drm/drm-misc/commit/?id=ca5442ed8f53

The fix is supposed to reach v6.11 tree, hence wondering if this fall
through the cracks as it haven't shown up in -rc1, neither in linux-next
- should have been applied to drm-misc-fixes instead of drm-misc?!

Sorry for the noise if this already follows the regular DRM workflow and
just needs more time to get picked into the target branches.

Thanks,
Cristian

Re: [PATCH] drm/bridge-connector: Fix double free in error handling paths

[Robert Foss]

On Wed, Jul 31, 2024 at 10:03 PM Cristian Ciocaltea
<cristian.ciocaltea@collabora.com> wrote:
>
> Hi Robert,
>
> On 7/18/24 3:02 PM, Robert Foss wrote:
> > On Thu, 11 Jul 2024 14:26:55 +0300, Cristian Ciocaltea wrote:
> >> The recent switch to drmm allocation in drm_bridge_connector_init() may
> >> cause double free on bridge_connector in some of the error handling
> >> paths.
> >>
> >> Drop the explicit kfree() calls on bridge_connector.
> >>
> >>
> >> [...]
> >
> > Applied, thanks!
> >
> > [1/1] drm/bridge-connector: Fix double free in error handling paths
> >       https://cgit.freedesktop.org/drm/drm-misc/commit/?id=ca5442ed8f53
>
> The fix is supposed to reach v6.11 tree, hence wondering if this fall
> through the cracks as it haven't shown up in -rc1, neither in linux-next
> - should have been applied to drm-misc-fixes instead of drm-misc?!

I'm seeing the commit in linux-next.

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/?qt=grep&q=drm/bridge-connector:+Fix+double+free+in+error+handling+paths

It was probably submitted to drm-misc-next, and not drm-misc-fixes and
thereby missed 6.11 inclusion. Let me push it to drm-misc-fixes too.


>
> Sorry for the noise if this already follows the regular DRM workflow and
> just needs more time to get picked into the target branches.
>
> Thanks,
> Cristian
>

Re: [PATCH] drm/bridge-connector: Fix double free in error handling paths

[Robert Foss]

On Thu, 11 Jul 2024 14:26:55 +0300, Cristian Ciocaltea wrote:
> The recent switch to drmm allocation in drm_bridge_connector_init() may
> cause double free on bridge_connector in some of the error handling
> paths.
> 
> Drop the explicit kfree() calls on bridge_connector.
> 
> 
> [...]

Applied, thanks!

[1/1] drm/bridge-connector: Fix double free in error handling paths
      (no commit info)



Rob