drm/msm/mdp5: check the return of kzalloc()

[ Upstream commit 047ae665577776b7feb11bd4f81f46627cff95e7 ]

kzalloc() is a memory allocation function which can return NULL when
some internal memory errors happen. So it is better to check it to
prevent potential wrong memory access.

Besides, since mdp5_plane_reset() is void type, so we should better
set `plane-state` to NULL after releasing it.

Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/481055/
Link: https://lore.kernel.org/r/tencent_8E2A1C78140EE1784AB2FF4B2088CC0AB908@qq.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
index 83423092de2ff7cbdcb5ccb3b5fed7052e588477..da0799333970285d4d59e7cbc8a95ddd22ccbb11 100644 (file)
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
@@ -179,7 +179,10 @@ static void mdp5_plane_reset(struct drm_plane *plane)
                drm_framebuffer_put(plane->state->fb);
 
        kfree(to_mdp5_plane_state(plane->state));
+       plane->state = NULL;
        mdp5_state = kzalloc(sizeof(*mdp5_state), GFP_KERNEL);
+       if (!mdp5_state)
+               return;
 
        /* assign default blend parameters */
        mdp5_state->alpha = 255;