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)
committerAurelien Jarno <aurel32@debian.org>
Fri, 2 Mar 2018 07:52:22 +0000 (07:52 +0000)
commit1a827090ab1754c8e72e972cc01bba95bd50041c
tree2a3897ce227ae056aec63d782d53416bc4d3b715
parent8abd472cd3070343c6fcb9cabc379e9dd6e862c3
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