[PATCH 4.4 47/53] ASoC: rsnd: Add missing initialization of ADG req_rate

From: Greg Kroah-Hartman
Date: Mon Aug 28 2017 - 04:29:38 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

commit 8b27418f300cafbdbbb8cfa9c29d398ed34d6723 upstream.

If the "clock-frequency" DT property is not found, req_rate is used
uninitialized, and the "audio_clkout" clock will be created with an
arbitrary clock rate.

This uninitialized kernel stack data may leak to userspace through
/sys/kernel/debug/clk/clk_summary, cfr. the value in the "rate" column:

clock enable_cnt prepare_cnt rate accuracy phase
--------------------------------------------------------------------
audio_clkout 0 0 4001836240 0 0

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Thong Ho <thong.ho.px@xxxxxxxxxxxxxxx>
Signed-off-by: Nhan Nguyen <nhan.nguyen.yb@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
sound/soc/sh/rcar/adg.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/sound/soc/sh/rcar/adg.c
+++ b/sound/soc/sh/rcar/adg.c
@@ -437,7 +437,7 @@ static void rsnd_adg_get_clkout(struct r
struct device *dev = rsnd_priv_to_dev(priv);
struct device_node *np = dev->of_node;
u32 ckr, rbgx, rbga, rbgb;
- u32 rate, req_rate, div;
+ u32 rate, req_rate = 0, div;
uint32_t count = 0;
unsigned long req_48kHz_rate, req_441kHz_rate;
int i;