From b0c8fdc7fdb77586c3d1937050925b960743306e Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 19 Aug 2019 17:18:00 -0700 Subject: lockdown: Lock down perf when in confidentiality mode Disallow the use of certain perf facilities that might allow userspace to access kernel data. Signed-off-by: David Howells Signed-off-by: Matthew Garrett Reviewed-by: Kees Cook Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Signed-off-by: James Morris --- kernel/events/core.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'kernel') diff --git a/kernel/events/core.c b/kernel/events/core.c index f85929ce13be..8732f980a4fc 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10798,6 +10798,13 @@ SYSCALL_DEFINE5(perf_event_open, perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) return -EACCES; + err = security_locked_down(LOCKDOWN_PERF); + if (err && (attr.sample_type & PERF_SAMPLE_REGS_INTR)) + /* REGS_INTR can leak data, lockdown must prevent this */ + return err; + + err = 0; + /* * In cgroup mode, the pid argument is used to pass the fd * opened to the cgroup directory in cgroupfs. The cpu argument -- cgit v1.2.3