On 8/24/19 11:19 AM, Pavel Machek wrote:
On Fri 2019-08-23 01:10:49, tip-bot2 for Tom Lendacky wrote:
The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: c49a0a80137c7ca7d6ced4c812c9e07a949f6f24 Gitweb: https://git.kernel.org/tip/c49a0a80137c7ca7d6ced4c812c9e07a949f6f24 Author: Tom Lendacky thomas.lendacky@amd.com AuthorDate: Mon, 19 Aug 2019 15:52:35 Committer: Borislav Petkov bp@suse.de CommitterDate: Mon, 19 Aug 2019 19:42:52 +02:00
x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h
There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly.
There are quite a few unanswered questions here.
a) Is there/should there be CVE for this?
b) Can we perform proper steps in kernel, thus making RDRAND usable even when BIOS is buggy?
The kernel should at least be able to set its internal "CPUID" bit, visible through /proc/cpuinfo.
-hpa