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

From: PaX Team
Date: Fri Feb 24 2012 - 18:15:34 EST


On 24 Feb 2012 at 14:04, David Windsor wrote:

> Suggestions on recovering from an overflow here?

do what PaX does? :)

1. saturate the refcount
2. report the event (pax_report_refcount_overflow)
3. kill the triggering userland process (this may be optional but it's a good measure
if you have stuff like grsecurity's lockout feature)

> 2. Detect the overflow before it happens, don't increment the counter,
> issue a warning but no BUG.
> This could also lead to some "undefined" behavior in subsystems.

it's called a memory leak :).

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