drm/amd/display: Fix potential index out of bounds in color transformation function

[ Upstream commit 63ae548f1054a0b71678d0349c7dc9628ddd42ca ]

Fixes index out of bounds issue in the color transformation function.
The issue could occur when the index 'i' exceeds the number of transfer
function points (TRANSFER_FUNC_POINTS).

The fix adds a check to ensure 'i' is within bounds before accessing the
transfer function points. If 'i' is out of bounds, an error message is
logged and the function returns false to indicate an error.

Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:405 cm_helper_translate_curve_to_hw_format() error: buffer overflow 'output_tf->tf_pts.red' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:406 cm_helper_translate_curve_to_hw_format() error: buffer overflow 'output_tf->tf_pts.green' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:407 cm_helper_translate_curve_to_hw_format() error: buffer overflow 'output_tf->tf_pts.blue' 1025 <= s32max

Fixes: b629596072e5 ("drm/amd/display: Build unity lut for shaper")
Cc: Vitaly Prosyak <vitaly.prosyak@amd.com>
Cc: Charlene Liu <Charlene.Liu@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Roman Li <roman.li@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Cc: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c
index 3538973bd0c6cb7a23a7ffdd2f70883e354ed34f..c0372aa4ec838033a3b6f4f23d603fd57bd8f8fc 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c
@@ -382,6 +382,11 @@ bool cm_helper_translate_curve_to_hw_format(struct dc_context *ctx,
                                i += increment) {
                        if (j == hw_points - 1)
                                break;
+                       if (i >= TRANSFER_FUNC_POINTS) {
+                               DC_LOG_ERROR("Index out of bounds: i=%d, TRANSFER_FUNC_POINTS=%d\n",
+                                            i, TRANSFER_FUNC_POINTS);
+                               return false;
+                       }
                        rgb_resulted[j].red = output_tf->tf_pts.red[i];
                        rgb_resulted[j].green = output_tf->tf_pts.green[i];
                        rgb_resulted[j].blue = output_tf->tf_pts.blue[i];