[PATCH 6.1 258/451] drm/amd/display: Fix potential NULL pointer dereferences in 'dcn10_set_output_transfer_func()'

Sasha Levin
2024-03-24T23:16:20Z

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/dcn10/dcn10_hw_sequencer.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
index 009b5861a3fec..d6c5d48c878ec 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
@@ -1854,6 +1854,9 @@ 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;

@@ -1876,8 +1879,8 @@ 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