[FFmpeg-devel] [PATCH] NellyMoser audio decoder

Rich Felker dalias
Thu Sep 13 00:33:23 CEST 2007

On Wed, Sep 12, 2007 at 05:42:05PM +0200, Reimar D?ffinger wrote:
> Hello,
> On Wed, Sep 12, 2007 at 10:50:23AM -0400, Daniel Serpell wrote:
> > Well, with a 128 bit hash, and 2^20 pages (so you have 4GB virtual RAM),
> > the probability of collision is (1-e(- (2^40) / (2^129))) = 1.6*10^-27
> You can't do blind probability calculation for things that are very,
> very far from random (the content of the pages on a PC in no way qualify
> as random).
> That is the same fallacy as the Intel FDIV bug that "should" not have
> been noticed according to such calculations.
> Nevertheless, this would entirely be an option before resorting to
> things like an OOM killer, and in some applications it might be even
> faster (namely when not using it to find duplicates among already
> swapped out memory, but for finding duplicates in the current memory
> before/instead of).
> But before someone tries it out it is hard to tell if it makes any sense
> in real-world situations...

OOM killer is much less bad than giving an attacker root.


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