drm/bridge: properly refcount DT nodes in aux bridge drivers

The aux-bridge and aux-hpd-bridge drivers didn't call of_node_get() on
the device nodes further used for dev->of_node and platform data. When
bridge devices are released, the reference counts are decreased,
resulting in refcount underflow / use-after-free warnings. Get
corresponding refcounts during AUX bridge allocation.

Reported-by: Luca Weiss <luca.weiss@fairphone.com>
Fixes: 2a04739139 ("drm/bridge: add transparent bridge helper")
Fixes: 26f4bac3d8 ("drm/bridge: aux-hpd: Replace of_device.h with explicit include")
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231216235910.911958-1-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
This commit is contained in:
Dmitry Baryshkov 2023-12-17 01:59:10 +02:00
parent 8a53e29fe0
commit 6914968a0b
2 changed files with 4 additions and 3 deletions

View File

@ -6,6 +6,7 @@
*/
#include <linux/auxiliary_bus.h>
#include <linux/module.h>
#include <linux/of.h>
#include <drm/drm_bridge.h>
#include <drm/bridge/aux-bridge.h>
@ -57,7 +58,7 @@ int drm_aux_bridge_register(struct device *parent)
adev->id = ret;
adev->name = "aux_bridge";
adev->dev.parent = parent;
adev->dev.of_node = parent->of_node;
adev->dev.of_node = of_node_get(parent->of_node);
adev->dev.release = drm_aux_bridge_release;
ret = auxiliary_device_init(adev);

View File

@ -68,9 +68,9 @@ struct device *drm_dp_hpd_bridge_register(struct device *parent,
adev->id = ret;
adev->name = "dp_hpd_bridge";
adev->dev.parent = parent;
adev->dev.of_node = parent->of_node;
adev->dev.of_node = of_node_get(parent->of_node);
adev->dev.release = drm_aux_hpd_bridge_release;
adev->dev.platform_data = np;
adev->dev.platform_data = of_node_get(np);
ret = auxiliary_device_init(adev);
if (ret) {