Re: [PATCH v2] kernfs: Fix kernfs_name_compare

From: Tejun Heo
Date: Mon Jan 05 2015 - 09:13:54 EST


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?

Thanks.

--
tejun
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