FROMLIST: security,perf: Allow further restriction of perf_event_open
When kernel.perf_event_open is set to 3 (or greater), disallow all
access to performance events by users without CAP_SYS_ADMIN.
Add a Kconfig symbol CONFIG_SECURITY_PERF_EVENTS_RESTRICT that
makes this value the default.
This is based on a similar feature in grsecurity
(CONFIG_GRKERNSEC_PERF_HARDEN). This version doesn't include making
the variable read-only. It also allows enabling further restriction
at run-time regardless of whether the default is changed.
https://lkml.org/lkml/2016/1/11/587
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Bug: 29054680
Change-Id: Iff5bff4fc1042e85866df9faa01bce8d04335ab8
diff --git a/security/Kconfig b/security/Kconfig
index ccc61f8..f9e267c 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -84,6 +84,15 @@
If you are unsure how to answer this question, answer N.
+config SECURITY_PERF_EVENTS_RESTRICT
+ bool "Restrict unprivileged use of performance events"
+ depends on PERF_EVENTS
+ help
+ If you say Y here, the kernel.perf_event_paranoid sysctl
+ will be set to 3 by default, and no unprivileged use of the
+ perf_event_open syscall will be permitted unless it is
+ changed.
+
config SECURITY
bool "Enable different security models"
depends on SYSFS