diff -Naur blender-2.68a-original/source/blender/imbuf/intern/rotate.c blender-2.68a/source/blender/imbuf/intern/rotate.c
--- blender-2.68a-original/source/blender/imbuf/intern/rotate.c	2012-08-12 19:28:33.000000000 -0400
+++ blender-2.68a/source/blender/imbuf/intern/rotate.c	2022-05-02 10:20:19.526407543 -0400
@@ -43,28 +43,30 @@
 
 void IMB_flipy(struct ImBuf *ibuf)
 {
-	int x, y;
+	size_t x_size, y_size, stride;
 
 	if (ibuf == NULL) return;
 
 	if (ibuf->rect) {
 		unsigned int *top, *bottom, *line;
 
-		x = ibuf->x;
-		y = ibuf->y;
+		x_size = ibuf->x;
+		y_size = ibuf->y;
+
+		stride = x_size * sizeof(int);
 
 		top = ibuf->rect;
-		bottom = top + ((y - 1) * x);
-		line = MEM_mallocN(x * sizeof(int), "linebuf");
+		bottom = top + ((y_size - 1) * x_size);
+		line = MEM_mallocN(stride, "linebuf");
 	
-		y >>= 1;
+		y_size >>= 1;
 
-		for (; y > 0; y--) {
-			memcpy(line, top, x * sizeof(int));
-			memcpy(top, bottom, x * sizeof(int));
-			memcpy(bottom, line, x * sizeof(int));
-			bottom -= x;
-			top += x;
+		for (; y_size > 0; y_size--) {
+			memcpy(line, top, stride);
+			memcpy(top, bottom, stride);
+			memcpy(bottom, line, stride);
+			bottom -= x_size;
+			top += x_size;
 		}
 
 		MEM_freeN(line);
@@ -73,21 +75,23 @@
 	if (ibuf->rect_float) {
 		float *topf = NULL, *bottomf = NULL, *linef = NULL;
 
-		x = ibuf->x;
-		y = ibuf->y;
+		x_size = ibuf->x;
+		y_size = ibuf->y;
+
+		stride = x_size * 4 * sizeof(float);
 
 		topf = ibuf->rect_float;
-		bottomf = topf + 4 * ((y - 1) * x);
-		linef = MEM_mallocN(4 * x * sizeof(float), "linebuff");
+		bottomf = topf + 4 * ((y_size - 1) * x_size);
+		linef = MEM_mallocN(stride, "linebuf");
 
-		y >>= 1;
+		y_size >>= 1;
 
-		for (; y > 0; y--) {
-			memcpy(linef, topf, 4 * x * sizeof(float));
-			memcpy(topf, bottomf, 4 * x * sizeof(float));
-			memcpy(bottomf, linef, 4 * x * sizeof(float));
-			bottomf -= 4 * x;
-			topf += 4 * x;
+		for (; y_size > 0; y_size--) {
+			memcpy(linef, topf, stride);
+			memcpy(topf, bottomf, stride);
+			memcpy(bottomf, linef, stride);
+			bottomf -= 4 * x_size;
+			topf += 4 * x_size;
 		}
 
 		MEM_freeN(linef);
@@ -106,18 +110,20 @@
 
 	if (ibuf->rect) {
 		for (yi = y - 1; yi >= 0; yi--) {
+			const size_t x_offset = (size_t)x * yi;
 			for (xr = x - 1, xl = 0; xr >= xl; xr--, xl++) {
-				SWAP(unsigned int, ibuf->rect[(x * yi) + xr], ibuf->rect[(x * yi) + xl]);
+				SWAP(unsigned int, ibuf->rect[x_offset + xr], ibuf->rect[x_offset + xl]);
 			}
 		}
 	}
 	
 	if (ibuf->rect_float) {
 		for (yi = y - 1; yi >= 0; yi--) {
+			const size_t x_offset = (size_t)x * yi;
 			for (xr = x - 1, xl = 0; xr >= xl; xr--, xl++) {
-				memcpy(&px_f, &ibuf->rect_float[((x * yi) + xr) * 4], 4 * sizeof(float));
-				memcpy(&ibuf->rect_float[((x * yi) + xr) * 4], &ibuf->rect_float[((x * yi) + xl) * 4], 4 * sizeof(float));
-				memcpy(&ibuf->rect_float[((x * yi) + xl) * 4], &px_f, 4 * sizeof(float));
+				memcpy(&px_f, &ibuf->rect_float[(x_offset + xr) * 4], sizeof(float[4]));
+				memcpy(&ibuf->rect_float[(x_offset + xr) * 4], &ibuf->rect_float[(x_offset + xl) * 4], sizeof(float[4]));
+				memcpy(&ibuf->rect_float[(x_offset + xl) * 4], &px_f, sizeof(float[4]));
 			}
 		}
 	}