[PATCH] drm/i915/gvt: Fix out-of-bounds buffer write into opregion->signature[]

[Chris Wilson]

sparse spots

drivers/gpu/drm/i915/gvt/opregion.c:234 alloc_and_init_virt_opregion() error: memcpy() 'header->signature' too small (16 vs 17)

as gvt is indeed trying to memcpy a string longer than the signature[].

Fixes: b2d6ef70614e ("drm/i915/gvt: Let each vgpu has separate opregion memory")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Xiong Zhang <xiong.y.zhang at intel.com>
Cc: Zhenyu Wang <zhenyuw at linux.intel.com>
Cc: Zhi Wang <zhi.a.wang at intel.com>
Cc: intel-gvt-dev at lists.freedesktop.org
---
 drivers/gpu/drm/i915/gvt/opregion.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gvt/opregion.c b/drivers/gpu/drm/i915/gvt/opregion.c
index 80720e59723a..3cf4c6f18152 100644
--- a/drivers/gpu/drm/i915/gvt/opregion.c
+++ b/drivers/gpu/drm/i915/gvt/opregion.c
@@ -232,7 +232,7 @@ static int alloc_and_init_virt_opregion(struct intel_vgpu *vgpu)
 	buf = (u8 *)vgpu_opregion(vgpu)->va;
 	header = (struct opregion_header *)buf;
 	memcpy(header->signature, OPREGION_SIGNATURE,
-			sizeof(OPREGION_SIGNATURE));
+			sizeof(OPREGION_SIGNATURE) - 1);
 	header->size = 0x8;
 	header->opregion_ver = 0x02000000;
 	header->mboxes = MBOX_VBT;
-- 
2.15.0