Re: [kernel-hardening] Re: Add overflow protection to kref

From: PaX Team
Date: Fri Feb 24 2012 - 18:00:45 EST


On 24 Feb 2012 at 23:13, Vasiliy Kulikov wrote:

> > But in this case, the principle does not apply because we can recover.
> > The reason we cannot recover from the stack protector case is because
> > the stack protector is reacting after the fact, which is not the case
> > here. Simply peg the reference count at the maximum value, neither
> > incrementing it nor decrementing it further.
>
> ...and simply loose one reference, which leads to use-after-free.

saturating the refcount keeps the protected object allocated, so it is
a memory leak, but it is not a use-after-free.

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