Re: [PATCH] acpi / apei: fix NULL deref during init

Re: [PATCH] acpi / apei: fix NULL deref during init

[Borislav Petkov]

On Fri, Dec 14, 2018 at 11:42:01PM +0100, Thomas Schöbel-Theuer wrote:
> Ah, I overlooked that commit e56c92565dfe2 is already providing a different
> solution to the same problem in newer kernels _only_, as a _side_ effect
> (not clear to me from the description, but clear from reading the code).

Damn, I missed the fact that this is not the upstream kernel:

CPU: 0 PID: 1 UID: 0 Comm: swapper/0 Not tainted 4.4.0-ui18344.004-uiabi1-infong-amd64 #1

> So another alternative would be backporting e56c92565dfe2 to the 4.4 LTS
> series. Also fine for me.

That looks like the right fix.

A note for the next time: do not send a fix for a stable kernel which is
not upstream:

>From Documentation/process/stable-kernel-rules.rst:

" - It or an equivalent fix must already exist in Linus' tree (upstream)."

The stable kernels track upstream so if a stable kernel has a problem,
the first thing one needs to do is to check whether this has been fixed
upstream and if so, to backport it. This is the case most of the time.
In the very seldom cases where a separate fix is needed, it needs to be
handled by asking Greg what to do. :-)

Adding stable@ folks to CC to set me straight if I'm missing something.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

Re: [PATCH] acpi / apei: fix NULL deref during init

[Greg KH]

On Fri, Dec 14, 2018 at 11:54:28PM +0100, Borislav Petkov wrote:
> On Fri, Dec 14, 2018 at 11:42:01PM +0100, Thomas Sch�bel-Theuer wrote:
> > Ah, I overlooked that commit e56c92565dfe2 is already providing a different
> > solution to the same problem in newer kernels _only_, as a _side_ effect
> > (not clear to me from the description, but clear from reading the code).
> 
> Damn, I missed the fact that this is not the upstream kernel:
> 
> CPU: 0 PID: 1 UID: 0 Comm: swapper/0 Not tainted 4.4.0-ui18344.004-uiabi1-infong-amd64 #1
> 
> > So another alternative would be backporting e56c92565dfe2 to the 4.4 LTS
> > series. Also fine for me.
> 
> That looks like the right fix.
> 
> A note for the next time: do not send a fix for a stable kernel which is
> not upstream:
> 
> >From Documentation/process/stable-kernel-rules.rst:
> 
> " - It or an equivalent fix must already exist in Linus' tree (upstream)."
> 
> The stable kernels track upstream so if a stable kernel has a problem,
> the first thing one needs to do is to check whether this has been fixed
> upstream and if so, to backport it. This is the case most of the time.
> In the very seldom cases where a separate fix is needed, it needs to be
> handled by asking Greg what to do. :-)
> 
> Adding stable@ folks to CC to set me straight if I'm missing something.

Nope, you are correct, thanks!

greg k-h