From c96988b7d99327bb08bd9efd29a203b22cd88ace Mon Sep 17 00:00:00 2001
From: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Date: Tue, 6 Dec 2022 16:05:17 +0800
Subject: [PATCH] drm/msm/dpu: Add check for cstate
Git-commit: c96988b7d99327bb08bd9efd29a203b22cd88ace
Patch-mainline: v6.3-rc1
References: git-fixes

As kzalloc may fail and return NULL pointer,
it should be better to check cstate
in order to avoid the NULL pointer dereference
in __drm_atomic_helper_crtc_reset.

Fixes: 1cff7440a86e ("drm/msm: Convert to using __drm_atomic_helper_crtc_reset() for reset.")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/514163/
Link: https://lore.kernel.org/r/20221206080517.43786-1-jiasheng@iscas.ac.cn
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index 41819039dd5e..175d2557e43c 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -968,7 +968,10 @@ static void dpu_crtc_reset(struct drm_crtc *crtc)
 	if (crtc->state)
 		dpu_crtc_destroy_state(crtc, crtc->state);
 
-	__drm_atomic_helper_crtc_reset(crtc, &cstate->base);
+	if (cstate)
+		__drm_atomic_helper_crtc_reset(crtc, &cstate->base);
+	else
+		__drm_atomic_helper_crtc_reset(crtc, NULL);
 }
 
 /**
-- 
2.35.3