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)
committerBen Hutchings <ben@decadent.org.uk>
Wed, 4 Jan 2017 19:39:36 +0000 (19:39 +0000)
commitcae02044082c05a30e100e4a14d5a7526bdb2269
treea93c55ea25f474596cfa0aeac80e13e66f6dd743
parentdc1d008209ec102b05156ad42c37b0911d8732be
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