Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/core

1 files changed, 30 insertions, 1 deletions

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 39c059c..19a359d 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -21,17 +21,46 @@ typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
 /* Count the events in use (per event id, not per instance) */
 static int	total_ref_count;
 
+static int perf_trace_event_perm(struct ftrace_event_call *tp_event,
+				 struct perf_event *p_event)
+{
+	/* No tracing, just counting, so no obvious leak */
+	if (!(p_event->attr.sample_type & PERF_SAMPLE_RAW))
+		return 0;
+
+	/* Some events are ok to be traced by non-root users... */
+	if (p_event->attach_state == PERF_ATTACH_TASK) {
+		if (tp_event->flags & TRACE_EVENT_FL_CAP_ANY)
+			return 0;
+	}
+
+	/*
+	 * ...otherwise raw tracepoint data can be a severe data leak,
+	 * only allow root to have these.
+	 */
+	if (perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	return 0;
+}
+
 static int perf_trace_event_init(struct ftrace_event_call *tp_event,
 				 struct perf_event *p_event)
 {
 	struct hlist_head __percpu *list;
-	int ret = -ENOMEM;
+	int ret;
 	int cpu;
 
+	ret = perf_trace_event_perm(tp_event, p_event);
+	if (ret)
+		return ret;
+
 	p_event->tp_event = tp_event;
 	if (tp_event->perf_refcount++ > 0)
 		return 0;
 
+	ret = -ENOMEM;
+
 	list = alloc_percpu(struct hlist_head);
 	if (!list)
 		goto fail;