From f8195e5910785218ed53bc7e522cb31dad26401b Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Tue, 20 Nov 2018 17:17:45 +0000 Subject: [PATCH] drm/amd/display: fix dereference of pointer fs_params before it is null checked Currently there are several instances of pointer fs_params being dereferenced before fs_params is being null checked. Fix this by only dereferencing fs_params after the null check. Detected by CoverityScan, CID#1475565 ("Dereference before null check") Fixes: e1e8a020c6b8 ("drm/amd/display: Add support for Freesync 2 HDR and Content to Display Mapping") Signed-off-by: Colin Ian King Reviewed-by: Leo Li Signed-off-by: Alex Deucher --- .../drm/amd/display/modules/color/color_gamma.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c index 7480f072c375..bbecbaefb741 100644 --- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c +++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c @@ -813,20 +813,26 @@ static bool build_freesync_hdr(struct pwl_float_data_ex *rgb_regamma, const struct hw_x_point *coord_x = coordinate_x; struct fixed31_32 scaledX = dc_fixpt_zero; struct fixed31_32 scaledX1 = dc_fixpt_zero; - struct fixed31_32 max_display = dc_fixpt_from_int(fs_params->max_display); - struct fixed31_32 min_display = dc_fixpt_from_fraction(fs_params->min_display, 10000); - struct fixed31_32 max_content = dc_fixpt_from_int(fs_params->max_content); - struct fixed31_32 min_content = dc_fixpt_from_fraction(fs_params->min_content, 10000); + struct fixed31_32 max_display; + struct fixed31_32 min_display; + struct fixed31_32 max_content; + struct fixed31_32 min_content; struct fixed31_32 clip = dc_fixpt_one; struct fixed31_32 output; bool use_eetf = false; bool is_clipped = false; - struct fixed31_32 sdr_white_level = dc_fixpt_from_int(fs_params->sdr_white_level); + struct fixed31_32 sdr_white_level; if (fs_params == NULL || fs_params->max_content == 0 || fs_params->max_display == 0) return false; + max_display = dc_fixpt_from_int(fs_params->max_display); + min_display = dc_fixpt_from_fraction(fs_params->min_display, 10000); + max_content = dc_fixpt_from_int(fs_params->max_content); + min_content = dc_fixpt_from_fraction(fs_params->min_content, 10000); + sdr_white_level = dc_fixpt_from_int(fs_params->sdr_white_level); + if (fs_params->min_display > 1000) // cap at 0.1 at the bottom min_display = dc_fixpt_from_fraction(1, 10); if (fs_params->max_display < 100) // cap at 100 at the top