From 03fc4cf45d30533d54f0f4ebc02aacfa12f52ce2 Mon Sep 17 00:00:00 2001
From: Mark Yacoub <markyacoub@chromium.org>
Date: Fri, 4 Jun 2021 13:01:07 -0400
Subject: [PATCH] drm/amd/display: Verify Gamma & Degamma LUT sizes in amdgpu_dm_atomic_check
Git-commit: 03fc4cf45d30533d54f0f4ebc02aacfa12f52ce2
Patch-mainline: v5.14-rc1
References: git-fixes

For each CRTC state, check the size of Gamma and Degamma LUTs  so
unexpected and larger sizes wouldn't slip through.

Test: IGT:kms_color::pipe-invalid-gamma-lut-sizes

V2: fix assignments in if clauses, Mark's email.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Mark Yacoub <markyacoub@chromium.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c       |    4 +
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h       |    1 
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c |   41 +++++++++++++---
 3 files changed, 40 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -7278,6 +7278,10 @@ static int amdgpu_dm_atomic_check(struct
 		    old_crtc_state->vrr_enabled == new_crtc_state->vrr_enabled)
 			continue;
 
+		ret = amdgpu_dm_verify_lut_sizes(new_crtc_state);
+		if (ret)
+			goto fail;
+
 		if (!new_crtc_state->enable)
 			continue;
 
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -398,6 +398,7 @@ void amdgpu_dm_crtc_handle_crc_irq(struc
 #define MAX_COLOR_LEGACY_LUT_ENTRIES 256
 
 void amdgpu_dm_init_color_mod(void);
+int amdgpu_dm_verify_lut_sizes(const struct drm_crtc_state *crtc_state);
 int amdgpu_dm_update_crtc_color_mgmt(struct dm_crtc_state *crtc);
 int amdgpu_dm_update_plane_color_mgmt(struct dm_crtc_state *crtc,
 				      struct dc_plane_state *dc_plane_state);
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
@@ -278,6 +278,37 @@ static int __set_input_tf(struct dc_tran
 }
 
 /**
+ * Verifies that the Degamma and Gamma LUTs attached to the |crtc_state| are of
+ * the expected size.
+ * Returns 0 on success.
+ */
+int amdgpu_dm_verify_lut_sizes(const struct drm_crtc_state *crtc_state)
+{
+	const struct drm_color_lut *lut = NULL;
+	uint32_t size = 0;
+
+	lut = __extract_blob_lut(crtc_state->degamma_lut, &size);
+	if (lut && size != MAX_COLOR_LUT_ENTRIES) {
+		DRM_DEBUG_DRIVER(
+			"Invalid Degamma LUT size. Should be %u but got %u.\n",
+			MAX_COLOR_LUT_ENTRIES, size);
+		return -EINVAL;
+	}
+
+	lut = __extract_blob_lut(crtc_state->gamma_lut, &size);
+	if (lut && size != MAX_COLOR_LUT_ENTRIES &&
+	    size != MAX_COLOR_LEGACY_LUT_ENTRIES) {
+		DRM_DEBUG_DRIVER(
+			"Invalid Gamma LUT size. Should be %u (or %u for legacy) but got %u.\n",
+			MAX_COLOR_LUT_ENTRIES, MAX_COLOR_LEGACY_LUT_ENTRIES,
+			size);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
  * amdgpu_dm_update_crtc_color_mgmt: Maps DRM color management to DC stream.
  * @crtc: amdgpu_dm crtc state
  *
@@ -311,14 +342,12 @@ int amdgpu_dm_update_crtc_color_mgmt(str
 	bool is_legacy;
 	int r;
 
-	degamma_lut = __extract_blob_lut(crtc->base.degamma_lut, &degamma_size);
-	if (degamma_lut && degamma_size != MAX_COLOR_LUT_ENTRIES)
-		return -EINVAL;
+	r = amdgpu_dm_verify_lut_sizes(&crtc->base);
+	if (r)
+		return r;
 
+	degamma_lut = __extract_blob_lut(crtc->base.degamma_lut, &degamma_size);
 	regamma_lut = __extract_blob_lut(crtc->base.gamma_lut, &regamma_size);
-	if (regamma_lut && regamma_size != MAX_COLOR_LUT_ENTRIES &&
-	    regamma_size != MAX_COLOR_LEGACY_LUT_ENTRIES)
-		return -EINVAL;
 
 	has_degamma =
 		degamma_lut && !__is_lut_linear(degamma_lut, degamma_size);