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-rw-r--r--kernel/trace/trace_event_perf.c31
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;
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