[PATCH 4.14 19/43] drm/msm/mdp5: check the return of kzalloc() - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Xiaoke Wang <xkernel.wang@foxmail.com>,
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	Rob Clark <robdclark@chromium.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 19/43] drm/msm/mdp5: check the return of kzalloc()
Date: Tue, 26 Apr 2022 10:21:01 +0200	[thread overview]
Message-ID: <20220426081735.085465556@linuxfoundation.org> (raw)
In-Reply-To: <20220426081734.509314186@linuxfoundation.org>

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/mdp/mdp5/mdp5_plane.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
index 4b22ac3413a1..1f9e3c5ea47d 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
@@ -197,7 +197,10 @@ static void mdp5_plane_reset(struct drm_plane *plane)
 		drm_framebuffer_unreference(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



