On Wed, Aug 09, 2023 at 05:22:02PM -0500, Limonciello, Mario wrote:
>
>
> On 8/9/2023 4:33 PM, Jason A. Donenfeld wrote:
> > Hey Greg,
> >
> > There was recently a bit of a snafoo with a maintainer taking the wrong
> > version of a patch and sending that up to Linus. That patch had
> > incorrect stable@ annotations and had a bug in it. That bug was fixed
> > with a follow up patch. But of course the metadata couldn't be changed
> > easily retroactively.
> >
> > So I'm emailing to ask you to backport these two patches back to 5.5:
> >
> > - 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs")
> > - cacc6e22932f ("tpm: Add a helper for checking hwrng enabled")
> >
> > I know the stable@ tag says 6.1+, but the actual right tags from the
> > newer versioned patch that didn't get picked are:
> >
> > Cc: stable@xxxxxxxxxxxxxxx # 5.5+
> > Fixes: b006c439d58d ("hwrng: core - start hwrng kthread also for untrusted sources")
> > Fixes: f1324bbc4011 ("tpm: disable hwrng for fTPM on some AMD designs")
> > Fixes: 3ef193822b25 ("tpm_crb: fix fTPM on AMD Zen+ CPUs")
> > Reported-by: daniil.stas@xxxxxxxxxx
> > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217719
> > Reported-by: bitlord0xff@xxxxxxxxx
> > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217212
> > Reviewed-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
> > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> >
> > Let me know if you need any more info.
> >
> > Thanks,
> > Jason
>
> So I had a quick try with the backports to see what happens. 6.1.y and
> 6.4.y apply cleanly no problem.
>
> However 5.15.y (and presumably 5.5.y) have a variety of issues that I
> think no longer make it a stable candidate. I started going down the
> rabbit hole of dependencies and it's massive unless hand modifications
> are done.
>
> Realistically the problem is most severe in 6.1.y because of
> b006c439d58d. I don't know it's worth going back any further.
Okay. Your (AMD's) hardware, so I'm fine deferring to your judgement.
Jason
