bpf, trace: check event type in bpf_perf_event_read

similar to bpf_perf_event_output() the bpf_perf_event_read() helper needs to check the type of the perf_event before reading the counter. Fixes: a43eec3 ("bpf: introduce bpf_perf_event_output() helper") Reported-by: Daniel Borkmann <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Daniel Borkmann <[email protected]> Signed-off-by: David S. Miller <[email protected]>
cluon · Jun 16, 2016 · ad572d1 · ad572d1
1 parent 19de99f
commit ad572d1
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
@@ -209,6 +209,10 @@ static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5)
 	    event->pmu->count)
 		return -EINVAL;
 
+	if (unlikely(event->attr.type != PERF_TYPE_HARDWARE &&
+		     event->attr.type != PERF_TYPE_RAW))
+		return -EINVAL;
+
 	/*
 	 * we don't know if the function is run successfully by the
 	 * return value. It can be judged in other places, such as