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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Cc: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>,
	Wyatt Wood <wyatt.wood@amd.com>,
	Anthony Koo <Anthony.Koo@amd.com>,
	Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>,
	Aurabindo Pillai <aurabindo.pillai@amd.com>,
	Alex Deucher <alexander.deucher@amd.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.7 418/713] drm/amd/display: Fix potential NULL pointer dereferences in 'dcn10_set_output_transfer_func()'
Date: Sun, 24 Mar 2024 18:42:24 -0400
Message-ID: <20240324224720.1345309-419-sashal@kernel.org>
In-Reply-To: <20240324224720.1345309-1-sashal@kernel.org>
References: <20240324224720.1345309-1-sashal@kernel.org>
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From: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>

[ Upstream commit 9ccfe80d022df7c595f1925afb31de2232900656 ]

The 'stream' pointer is used in dcn10_set_output_transfer_func() before
the check if 'stream' is NULL.

Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn10/dcn10_hwseq.c:1892 dcn10_set_output_transfer_func() warn: variable dereferenced before check 'stream' (see line 1875)

Fixes: ddef02de0d71 ("drm/amd/display: add null checks before logging")
Cc: Wyatt Wood <wyatt.wood@amd.com>
Cc: Anthony Koo <Anthony.Koo@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/display/dc/hwss/dcn10/dcn10_hwseq.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn10/dcn10_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn10/dcn10_hwseq.c
index 1fc8436c8130e..2b3ef5cdbd458 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/dcn10/dcn10_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn10/dcn10_hwseq.c
@@ -1834,6 +1834,9 @@ bool dcn10_set_output_transfer_func(struct dc *dc, struct pipe_ctx *pipe_ctx,
 {
 	struct dpp *dpp = pipe_ctx->plane_res.dpp;
 
+	if (!stream)
+		return false;
+
 	if (dpp == NULL)
 		return false;
 
@@ -1856,8 +1859,8 @@ bool dcn10_set_output_transfer_func(struct dc *dc, struct pipe_ctx *pipe_ctx,
 	} else
 		dpp->funcs->dpp_program_regamma_pwl(dpp, NULL, OPP_REGAMMA_BYPASS);
 
-	if (stream != NULL && stream->ctx != NULL &&
-			stream->out_transfer_func != NULL) {
+	if (stream->ctx &&
+	    stream->out_transfer_func) {
 		log_tf(stream->ctx,
 				stream->out_transfer_func,
 				dpp->regamma_params.hw_points_num);
-- 
2.43.0