oss-sec mailing list archives

Re: CVE-2023-20593: A use-after-free in AMD Zen2 Processors


From: Lucas Rolff <lucas () slcoding com>
Date: Tue, 25 Jul 2023 20:14:01 +0200

OS vendors can include it in microcode updates just fine assuming the change is minor (Spectre/Meltdown did take quite 
some time to iron out stability to live patch it).

On 25 Jul 2023, at 19:58, Demi Marie Obenour <demi () invisiblethingslab com> wrote:

On Tue, Jul 25, 2023 at 06:12:44PM +0100, Eddie Chapman wrote:
alice wrote:
this is a disaster of a security announcement from AMD. nothing is fixed
except for epyc. the only workaround anyone really has is the chicken bit,
thankfully.

Yes, very disappointing. Pure speculation; perhaps they were planning on
disclosing at the end of the year with full set of Microcode ready but
something we don't know (yet) forced them to disclose early. Who knows.

Does AMD make OS-loadable μcode patches available for client platforms,
or must all μcode loading on clients be done by the firmware?  If the
latter, then it will take a very long time for clients to get patched,
even if AMD released the updates promptly.  Also, server platforms can
usually reflash the firmware via the BMC, but client platforms do not
have this option.
-- 
Sincerely,
Demi Marie Obenour (she/her/hers)
Invisible Things Lab


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