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 7a00fe525dfbafa58cf5637b416330b4bb17d212..bd9bc51983fecbd66d0e18088313c0c7a3b99f96 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
@@ -379,6 +379,11 @@ bool cm_helper_translate_curve_to_hw_format(
                                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];