arm64: perf: fix event validation for software group leaders

commit ee7538a008a45050c8f706d38b600f55953169f9 upstream.

This is a port of c95eb3184ea1 ("ARM: 7809/1: perf: fix event validation
for software group leaders") to arm64, which fixes a panic in the arm64
perf backend found as a result of Vince's fuzzing tool.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 6c6f6c7166e9ee45e545eab850a2862a92c135b2)
Signed-off-by: Mark Brown <broonie@linaro.org>

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 2012646fb46f7d82a414d014f7e1f9c0b45f32e7..12e6ccb88691c65e6a20d761275babb1af369182 100644 (file)
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -322,6 +322,9 @@ validate_event(struct pmu_hw_events *hw_events,
        struct hw_perf_event fake_event = event->hw;
        struct pmu *leader_pmu = event->group_leader->pmu;
 
+       if (is_software_event(event))
+               return 1;
+
        if (event->pmu != leader_pmu || event->state <= PERF_EVENT_STATE_OFF)
                return 1;