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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, Jiasheng Jiang <jiasheng@iscas.ac.cn>,
        Brian Starkey <brian.starkey@arm.com>,
        Liviu Dudau <liviu.dudau@arm.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 208/667] drm: mali-dp: potential dereference of null pointer
Date:   Tue,  7 Jun 2022 18:57:53 +0200
Message-Id: <20220607164941.036735941@linuxfoundation.org>
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From: Jiasheng Jiang <jiasheng@iscas.ac.cn>

[ Upstream commit 73c3ed7495c67b8fbdc31cf58e6ca8757df31a33 ]

The return value of kzalloc() needs to be checked.
To avoid use of null pointer '&state->base' in case of the
failure of alloc.

Fixes: 99665d072183 ("drm: mali-dp: add malidp_crtc_state struct")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211214100837.46912-1-jiasheng@iscas.ac.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/arm/malidp_crtc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
index 494075ddbef6..b5928b52e279 100644
--- a/drivers/gpu/drm/arm/malidp_crtc.c
+++ b/drivers/gpu/drm/arm/malidp_crtc.c
@@ -487,7 +487,10 @@ static void malidp_crtc_reset(struct drm_crtc *crtc)
 	if (crtc->state)
 		malidp_crtc_destroy_state(crtc, crtc->state);
 
-	__drm_atomic_helper_crtc_reset(crtc, &state->base);
+	if (state)
+		__drm_atomic_helper_crtc_reset(crtc, &state->base);
+	else
+		__drm_atomic_helper_crtc_reset(crtc, NULL);
 }
 
 static int malidp_crtc_enable_vblank(struct drm_crtc *crtc)
-- 
2.35.1