Slashdot Mirror
Nvidia GPUs Can Leak Data From Google Chrome's Incognito Mode (softpedia.com)
An anonymous reader writes: Nvidia GPUs don't clear out memory that was previously allocated, and neither does Chrome before releasing memory back to the shared memory pool. When a user recently fired up Diablo 3 several hours after closing an Incognito Mode window that contained pornography, the game launched with snapshots of the last "private" browsing session appearing on the screen — revealing his prior activities. He says, "It's a fairly easy bug to fix. A patch to the GPU drivers could ensure that buffers are always erased before giving them to the application. It's what an operating system does with the CPU RAM, and it makes sense to use the same rules with a GPU. Additionally, Google Chrome could erase their GPU resources before quitting."
The AMD Open Source Driver on Linux do the same thing. It's not really a new or spectacular bug, graphics cards and drivers have done that stuff for quite a long while. Once there was also a fun bug that would make large texts in Firefox 'bleed' into the desktop background image, so it wasn't just showing old content, but actively manipulating content of another application.
The performance hit is real - and without custom silicon it's quite expensive. This bit me on the ass recently on a GPGPU project I was working because the amount of time taken to clear the buffer before use was about 10x the amount of time to actually do the computation.