"Potential leak of an object" when using Core Graphics - ios

Question

My app is drawing a shadow using the following code:
-(void)drawShadow:(CGContextRef)context rect:(CGRect)rect{
CGContextSaveGState(context);
//Set color of current context
[[UIColor blackColor] set];
//Set shadow and color of shadow
CGContextSetShadowWithColor(context, CGSizeMake(0, 2), 3, [[UIColor colorWithWhite:0 alpha:0.5] CGColor]);
CGContextFillEllipseInRect(context, rect);
CGContextClipToMask(context, rect, CGBitmapContextCreateImage(context));
CGContextRestoreGState(context); // Warning shows in this line
}
When I run Product > Analyze, it marks the last instruction of this block with the message: "Potential leak of an object". When I remove that line, it shows the same message but in the closing bracket.
Any idea of what I'm doing wrong?
Thanks

Answer 1

I think it's the CGBitmapContextCreateImage that is leaking.
Try assigning it to a local variable and then calling CGImageRelease with it once you've clipped to mask.
Another iPhone - CGBitmapContextCreateImage Leak

Answer 2

chedabob's answer worked! Here's the final code:
-(void)drawShadow:(CGContextRef)context rect:(CGRect)rect{
CGContextSaveGState(context);
//Set color of current context
[[UIColor blackColor] set];
//Set shadow and color of shadow
CGContextSetShadowWithColor(context, CGSizeMake(0, 2), 3, [[UIColor colorWithWhite:0 alpha:0.5] CGColor]);
CGContextFillEllipseInRect(context, rect);
CGImageRef bitmap = CGBitmapContextCreateImage(context);
CGContextClipToMask(context, rect, bitmap);
CGContextRestoreGState(context);
CGImageRelease(bitmap);
}