releases/5.4.191/drm-msm-mdp5-check-the-return-of-kzalloc.patch

From e6367a96cb9333fdf4cbfe8d84549e7c062b3b87 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Thu, 7 Apr 2022 10:31:51 +0800
Subject: drm/msm/mdp5: check the return of kzalloc()

From: Xiaoke Wang <xkernel.wang@foxmail.com>

[ 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>
---
 drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
index 83423092de2f..da0799333970 100644
--- 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;
-- 
2.35.1