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    SubjectRe: Security fix for remapping of page 0 (was [PATCH] Change ZERO_SIZE_PTR to point at unmapped space)
    Larry H. wrote:

    > Christopher, crippling the system is truly not the way to fix this.
    > There are many legitimate users of private|fixed mappings at 0. In
    > addition, if you want to go ahead and break POSIX, at least make sure
    > your patch closes the loophole.

    I suspect there aren't many at all, and restricting them through
    SELinux may be enough to mitigate the risk.

    > If SELinux isn't present, that's not useful. If mmap_min_addr is
    > enabled, that still won't solve what my original, utterly simple patch
    > fixes.

    Would anybody paranoid run their system without SELinux?

    > The patch provides a no-impact, clean solution to prevent kmalloc(0)
    > situations from becoming a security hazard. Nothing else.

    True, the changes in your patch only affect a few code paths.

    --
    All rights reversed.


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