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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 5.15 066/124] drm/msm/mdp5: check the return of kzalloc()
Date:   Tue, 26 Apr 2022 10:21:07 +0200
Message-Id: <20220426081749.177593375@linuxfoundation.org>
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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 c6b69afcbac8..50e854207c70 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
@@ -90,7 +90,10 @@ static void mdp5_plane_reset(struct drm_plane *plane)
 		__drm_atomic_helper_plane_destroy_state(plane->state);
 
 	kfree(to_mdp5_plane_state(plane->state));
+	plane->state = NULL;
 	mdp5_state = kzalloc(sizeof(*mdp5_state), GFP_KERNEL);
+	if (!mdp5_state)
+		return;
 
 	if (plane->type == DRM_PLANE_TYPE_PRIMARY)
 		mdp5_state->base.zpos = STAGE_BASE;
-- 
2.35.1