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@xxxxxxx> >> AuthorDate: Mon, 19 Aug 2019 15:52:35 >> Committer: Borislav Petkov <bp@xxxxxxx> >> 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