CoreImage Memory Termination Issue

Code Block swift
autoreleasepool{
                    let   fileName = captureFileName + String(currentIdx) + ".png"
                    if let imageRef = view.currentDrawable!.texture.toImage() {
                        let uiImage:UIImage = UIImage.init(cgImage: imageRef)
                        if let data = uiImage.jpegData(compressionQuality: 1.0) {
                            let filename = getDocumentsDirectory().appendingPathComponent(fileName)
                            try? data.write(to: filename)
                        }
                    }
}

Code Block swift
extension MTLTexture {
    func bytes() -> UnsafeMutableRawPointer {
        let width = self.width
        let height   = self.height
        let rowBytes = self.width * 4
        let p = malloc(width * height * 4)
        self.getBytes(p!, bytesPerRow: rowBytes, from: MTLRegionMake2D(0, 0, width, height), mipmapLevel: 0)
        return p!
    }
    func toImage() -> CGImage? {
        
        let p = bytes()
        let pColorSpace = CGColorSpaceCreateDeviceRGB()
        let rawBitmapInfo = CGImageAlphaInfo.noneSkipFirst.rawValue | CGBitmapInfo.byteOrder32Little.rawValue
        let bitmapInfo:CGBitmapInfo = CGBitmapInfo(rawValue: rawBitmapInfo)
        let selftureSize = self.width * self.height * 4
        let rowBytes = self.width * 4
        let releaseMaskImagePixelData: CGDataProviderReleaseDataCallback = { (info: UnsafeMutableRawPointer?, data: UnsafeRawPointer, size: Int) -> () in
            
            return
        }
        let provider = CGDataProvider(dataInfo: nil, data: p, size: selftureSize, releaseData: releaseMaskImagePixelData)
        let cgImageRef = CGImage(width: self.width, height: self.height, bitsPerComponent: 8, bitsPerPixel: 32, bytesPerRow: rowBytes, space: pColorSpace, bitmapInfo: bitmapInfo, provider: provider!, decode: nil, shouldInterpolate: true, intent: CGColorRenderingIntent.defaultIntent)!
        
        
        return cgImageRef
    }
}