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    Purported Nvidia Bug Could Resurrect Your Last Porn Session

    Written by

    Michael Byrne

    Editor

    Google doesn't make a whole lot of promises about Chrome's "incognito mode:"

    That said, it'd be nice to not have to worry about content from your most recent porn session being barfed back at you hours after shutting it down. This is apparently a real possibility, however, according to a software engineer/blogger who was faced with some supposedly forgotten porn reappearing later in the place of Diablo III's normally black loading screen.

    The engineer in question, Evan Andersen, writes:

    Even though this happened hours later, the contents of the incognito window were perfectly preserved.

    So how did this happen? A bug in Nvidia’s GPU drivers. GPU memory is not erased before giving it to an application. This allows the contents of one application to leak into another. When the Chrome incognito window was closed, it’s framebuffer was added to the pool of free GPU memory, but it was not erased. When Diablo requested a framebuffer of it’s own, Nvidia offered up the one previously used by Chrome. Since it wasn’t erased, it still contained the previous contents. Since Diablo doesn’t clear the buffer itself (as it should), the old incognito window was put on the screen again.

    Andersen wrote a program to test this out by scanning his GPU's memory for non-zero pixels. Some of the undead images were pretty screwed up, but he was able to resurrect a completely intact reddit page.

    As Andersen notes, the vulnerability effectively allows different users on the same machine to spy on each other, even completely by accident. He submitted bug reports to both Google and Nvidia, with the prior telling him that this is not really a bug because incognito mode is not intended to hide information among users. He says that Nvidia has acknowledged the problem, but has yet to implement a patch.

    I've reached out to Nvidia for comment and will update when and if I hear back.