From 07b72960d2b4a087ff2445e286159e69742069cc Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Thu, 17 Jun 2021 14:33:01 -0700
Subject: [PATCH] drm/i915/display: Do not zero past infoframes.vsc
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Git-commit: 07b72960d2b4a087ff2445e286159e69742069cc
Patch-mainline: v5.14-rc1
Alt-commit: c88e2647c5bb45d04dc4302018ebe6ebbf331823
References: git-fixes

intel_dp_vsc_sdp_unpack() was using a memset() size (36, struct dp_sdp)
larger than the destination (24, struct drm_dp_vsc_sdp), clobbering
fields in struct intel_crtc_state after infoframes.vsc. Use the actual
target size for the memset().

Fixes: 1b404b7dbb10 ("drm/i915/dp: Read out DP SDPs")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210617213301.1824728-1-keescook@chromium.org
(cherry picked from commit c88e2647c5bb45d04dc4302018ebe6ebbf331823)

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/display/intel_dp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 5c9222283044..6cc03b9e4321 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2868,7 +2868,7 @@ static int intel_dp_vsc_sdp_unpack(struct drm_dp_vsc_sdp *vsc,
 	if (size < sizeof(struct dp_sdp))
 		return -EINVAL;
 
-	memset(vsc, 0, size);
+	memset(vsc, 0, sizeof(*vsc));
 
 	if (sdp->sdp_header.HB0 != 0)
 		return -EINVAL;
-- 
2.26.2