Re: [PATCH] Fix SLAB freelist randomization duplicate entries

[Andrew Morton]

On Fri, 6 Jan 2017 09:58:48 -0800 Thomas Garnier <thgarnie@xxxxxxxxxx> wrote:

> On Thu, Jan 5, 2017 at 4:35 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> > On Tue,  3 Jan 2017 10:19:08 -0800 Thomas Garnier <thgarnie@xxxxxxxxxx> wrote:
> >
> >> This patch fixes a bug in the freelist randomization code. When a high
> >> random number is used, the freelist will contain duplicate entries. It
> >> will result in different allocations sharing the same chunk.
> >
> > Important: what are the user-visible runtime effects of the bug?
> 
> It will result in odd behaviours and crashes. It should be uncommon
> but it depends on the machines. We saw it happening more often on some
> machines (every few hours of running tests).

So should the fix be backported into -stable kernels?

> >
> >> Fixes: c7ce4f60ac19 ("mm: SLAB freelist randomization")
> >> Signed-off-by: John Sperbeck <jsperbeck@xxxxxxxxxx>
> >> Reviewed-by: Thomas Garnier <thgarnie@xxxxxxxxxx>
> >
> > This should have been signed off by yourself.
> >
> > I'm guessing that the author was in fact John?  If so, you should
> > indicate this by putting his From: line at the start of the changelog.
> > Otherwise, authorship will default to the sender (ie, yourself).
> >
> 
> Sorry, I though the sign-off was enough. Do you want me to send a v2?

I have the patch as

From: John Sperbeck <jsperbeck@xxxxxxxxxx>
Signed-off-by: John Sperbeck <jsperbeck@xxxxxxxxxx>
Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxx>

Is that correct?  Is John the primary author?