netdev - [PATCH net 2/2] bpf, trace: check event type in bpf_perf_event

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Date:	Wed, 15 Jun 2016 18:25:39 -0700
From:	Alexei Starovoitov <ast@...com>
To:	"David S . Miller" <davem@...emloft.net>
CC:	Daniel Borkmann <daniel@...earbox.net>,
	Sasha Goldshtein <goldshtn@...il.com>,
	<netdev@...r.kernel.org>, <kernel-team@...com>
Subject: [PATCH net 2/2] 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: a43eec304259 ("bpf: introduce bpf_perf_event_output() helper")
Reported-by: Daniel Borkmann <daniel@...earbox.net>
Signed-off-by: Alexei Starovoitov <ast@...nel.org>
Acked-by: Daniel Borkmann <daniel@...earbox.net>
---
the fix is minor. No need for stable backport.
---
 kernel/trace/bpf_trace.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index e7af6cb9d5cf..26f603da7e26 100644
--- 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
-- 
2.8.0