Code: void gdImageFill(gdImagePtr im, int x, int y, int nc)
{
	int l, x1, x2, dy;
	int oc;   /* old pixel value */
	int wx2,wy2;

	int alphablending_bak;

	/* stack of filled segments */
	/* struct seg stack[FILL_MAX],*sp = stack;; */
	struct seg *stack = NULL;
	struct seg *sp;

	if (!im->trueColor && nc > (im->colorsTotal -1)) {
 		return;
 	}
 
	alphablending_bak = im->alphaBlendingFlag;	
 	im->alphaBlendingFlag = 0;
 
 	if (nc==gdTiled){
		_gdImageFillTiled(im,x,y,nc);
		im->alphaBlendingFlag = alphablending_bak;
		return;
	}

 	wx2=im->sx;wy2=im->sy;
 	oc = gdImageGetPixel(im, x, y);
 	if (oc==nc || x<0 || x>wx2 || y<0 || y>wy2) {
		im->alphaBlendingFlag = alphablending_bak;	
 		return;
 	}
 
	/* Do not use the 4 neighbors implementation with
	 * small images
	 */
	if (im->sx < 4) {
		int ix = x, iy = y, c;
		do {
			do {
				c = gdImageGetPixel(im, ix, iy);
				if (c != oc) {
					goto done;
				}
				gdImageSetPixel(im, ix, iy, nc);
			} while(ix++ < (im->sx -1));
			ix = x;
		} while(iy++ < (im->sy -1));
		goto done;
	}

	stack = (struct seg *)safe_emalloc(sizeof(struct seg), ((int)(im->sy*im->sx)/4), 1);
	sp = stack;

	/* required! */
	FILL_PUSH(y,x,x,1);
	/* seed segment (popped 1st) */
 	FILL_PUSH(y+1, x, x, -1);
	while (sp>stack) {
		FILL_POP(y, x1, x2, dy);

		for (x=x1; x>=0 && gdImageGetPixel(im,x, y)==oc; x--) {
			gdImageSetPixel(im,x, y, nc);
		}
		if (x>=x1) {
			goto skip;
		}
		l = x+1;

                /* leak on left? */
		if (l<x1) {
			FILL_PUSH(y, l, x1-1, -dy);
		}
		x = x1+1;
		do {
			for (; x<=wx2 && gdImageGetPixel(im,x, y)==oc; x++) {
				gdImageSetPixel(im, x, y, nc);
			}
			FILL_PUSH(y, l, x-1, dy);
			/* leak on right? */
			if (x>x2+1) {
				FILL_PUSH(y, x2+1, x-1, -dy);
			}
skip:			for (x++; x<=x2 && (gdImageGetPixel(im, x, y)!=oc); x++);

			l = x;
		} while (x<=x2);
	}

 	efree(stack);
 
 done:
	im->alphaBlendingFlag = alphablending_bak;	
 }

Vulnerability Type: DoS Overflow 
CWE ID: CWE-190
Summary: Integer overflow in the gdImageCreate function in gd.c in the GD Graphics Library (aka libgd) before 2.0.34RC1, as used in PHP before 5.5.37, 5.6.x before 5.6.23, and 7.x before 7.0.8, allows remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted image dimensions.
Commit Message: iFixed bug #72446 - Integer Overflow in gdImagePaletteToTrueColor() resulting in heap overflow