Re: [PATCH v2] kernfs: Fix kernfs_name_compare

From: Greg Kroah-Hartman
Date: Mon Jan 05 2015 - 11:14:31 EST


On Mon, Jan 05, 2015 at 09:13:47AM -0500, Tejun Heo wrote:
> On Fri, Dec 05, 2014 at 11:41:33PM +0100, Rasmus Villemoes wrote:
> > Returning a difference from a comparison functions is usually wrong
> > (see acbbe6fbb240 "kcmp: fix standard comparison bug" for the long
> > story). Here there is the additional twist that if the void pointers
> > ns and kn->ns happen to differ by a multiple of 2^32,
> > kernfs_name_compare returns 0, falsely reporting a match to the
> > caller.
> >
> > Technically 'hash - kn->hash' is ok since the hashes are restricted to
> > 31 bits, but it's better to avoid that subtlety.
> >
> > Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
>
> Acked-by: Tejun Heo <tj@xxxxxxxxxx>
>
> And this is a -stable material. Greg, can you please pick this one
> up?

Will do, thanks.

greg k-h
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