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    SubjectRe: [reiserfs-list] major security bug in reiserfs (may affect SuSE Linux)


    On Wednesday, January 10, 2001 12:38:34 PM -0500 Alexander Viro
    <viro@math.psu.edu> wrote:

    > On Wed, 10 Jan 2001, Chris Mason wrote:
    >
    >> In filldir, I don't like the line where we ((char *)dirent += reclen ;
    >> If reclen is much larger than the buffer sent from userspace, I don't
    >> see how we stay in bounds.
    >
    > So? copy_to_user() and put_user() will refuse to scramble the
    > kernel memory. IOW, dirent can be out of the userspace. Hell, user could
    > call getdents() and pass it a kernel pointer. Try it and you'll see what
    > happens.
    >

    Ah thanks, that makes more sense. But, copy_to_user is only working on
    namelen bytes, and reclen is bigger than that. So, who is checking the
    value for the buf->current_dir pointer?

    -chris

    -
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