x86/cpu/amd: Add a Zenbleed fix
authorBorislav Petkov (AMD) <bp@alien8.de>
Sat, 15 Jul 2023 11:41:28 +0000 (13:41 +0200)
committerSalvatore Bonaccorso <carnil@debian.org>
Thu, 27 Jul 2023 22:17:15 +0000 (23:17 +0100)
commit94ff11dc7bd66dad3aa017705d8bc62ac28b13d0
tree5e21f39b2a3d19249a354a59d4e7e43d0ce21e0c
parentc0f2c08ca31bf9e307c087fa8497d5881fbf5508
x86/cpu/amd: Add a Zenbleed fix

Origin: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit?id=93df00f9d48d48466ddbe01a06eaaf3311ecfb53
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2023-20593

Upstream commit: 522b1d69219d8f083173819fde04f994aa051a98

Add a fix for the Zen2 VZEROUPPER data corruption bug where under
certain circumstances executing VZEROUPPER can cause register
corruption or leak data.

The optimal fix is through microcode but in the case the proper
microcode revision has not been applied, enable a fallback fix using
a chicken bit.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Gbp-Pq: Topic bugfix/x86
Gbp-Pq: Name x86-cpu-amd-Add-a-Zenbleed-fix.patch
arch/x86/include/asm/microcode.h
arch/x86/include/asm/microcode_amd.h
arch/x86/include/asm/msr-index.h
arch/x86/kernel/cpu/amd.c
arch/x86/kernel/cpu/common.c