drm/vmwgfx: Fix possible integer overflow

Cc: stable@vger.kernel.org
Reported-by: NBrian Paul <brianp@vmware.com>
Signed-off-by: NThomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: NJakob Bornecrantz <jakob@vmware.com>

drivers/gpu/drm/vmwgfx/svga3d_surfacedefs.h

@@ -38,8 +38,11 @@
 
 #define DIV_ROUND_UP(x, y)  (((x) + (y) - 1) / (y))
 #define max_t(type, x, y)  ((x) > (y) ? (x) : (y))
+#define min_t(type, x, y)  ((x) < (y) ? (x) : (y))
 #define surf_size_struct SVGA3dSize
 #define u32 uint32
+#define u64 uint64_t
+#define U32_MAX ((u32)~0U)
 
 #endif /* __KERNEL__ */
 
@@ -704,8 +707,8 @@ static const struct svga3d_surface_desc svga3d_surface_descs[] = {
 
 static inline u32 clamped_umul32(u32 a, u32 b)
 {
-	uint64_t tmp = (uint64_t) a*b;
-	return (tmp > (uint64_t) ((u32) -1)) ? (u32) -1 : tmp;
+	u64 tmp = (u64) a*b;
+	return (tmp > (u64) U32_MAX) ? U32_MAX : tmp;
 }
 
 static inline const struct svga3d_surface_desc *
@@ -834,7 +837,7 @@ svga3dsurface_get_serialized_size(SVGA3dSurfaceFormat format,
 				  bool cubemap)
 {
 	const struct svga3d_surface_desc *desc = svga3dsurface_get_desc(format);
-	u32 total_size = 0;
+	u64 total_size = 0;
 	u32 mip;
 
 	for (mip = 0; mip < num_mip_levels; mip++) {
@@ -847,7 +850,7 @@ svga3dsurface_get_serialized_size(SVGA3dSurfaceFormat format,
 	if (cubemap)
 		total_size *= SVGA3D_MAX_SURFACE_FACES;
 
-	return total_size;
+	return (u32) min_t(u64, total_size, (u64) U32_MAX);
 }