x86: Restrict MSR access when securelevel is set
authorMatthew Garrett <mjg59@srcf.ucam.org>
Fri, 8 Feb 2013 19:12:13 +0000 (11:12 -0800)
committerYves-Alexis Perez <corsac@debian.org>
Wed, 21 Feb 2018 15:29:03 +0000 (15:29 +0000)
commitaa5c8d9b215285ccb2f8a6c4cc5ce992a4b4cb62
treecff8be5b2e75190dafd107611f775edbb6971ae2
parent349c09774a3803edbc18ec6ff67ca7786b9fe15f
x86: Restrict MSR access when securelevel is set

Permitting write access to MSRs allows userspace to modify the running
kernel. Prevent this if securelevel has been set. Based on a patch by Kees
Cook.

Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>
Gbp-Pq: Topic features/all/securelevel
Gbp-Pq: Name x86-restrict-msr-access-when-securelevel-is-set.patch
arch/x86/kernel/msr.c