[alsa-devel] [PATCH] [RFC] ASoC: rsnd: Add missing initialization of ADG req_rate
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@glider.be --- Should the absence of this property be considered an error?
Documentation/devicetree/bindings/sound/renesas,rsnd.txt states that both "#clock-cells" and "clock-frequency" are required properties, but none of the R-Car Gen1 and Gen2 DTSes seem to have them? --- sound/soc/sh/rcar/adg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/soc/sh/rcar/adg.c b/sound/soc/sh/rcar/adg.c index 2a5b3a293cd243db..b123734f9fbdabd9 100644 --- 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 rsnd_priv *priv, 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;
Hi Geert
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 0Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be
Acked-by: Kuninori Morimoto kuninori.morimoto.gx@renesas.com
Should the absence of this property be considered an error?
Documentation/devicetree/bindings/sound/renesas,rsnd.txt states that both "#clock-cells" and "clock-frequency" are required properties, but none of the R-Car Gen1 and Gen2 DTSes seem to have them?
This clkout is option for each board will fix
On Wed, Oct 28, 2015 at 04:03:48PM +0100, Geert Uytterhoeven wrote:
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.
I'd expect that if we support a missing clock frequency property we'd read the state back from the hardware.
The patch
ASoC: rsnd: Add missing initialization of ADG req_rate
has been applied to the asoc tree at
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
From b212be688128b539bb2c69c5da25b04b5551f421 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven geert+renesas@glider.be Date: Wed, 28 Oct 2015 16:03:48 +0100 Subject: [PATCH] ASoC: rsnd: Add missing initialization of ADG req_rate
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@glider.be Acked-by: Kuninori Morimoto kuninori.morimoto.gx@renesas.com Signed-off-by: Mark Brown broonie@kernel.org --- sound/soc/sh/rcar/adg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/soc/sh/rcar/adg.c b/sound/soc/sh/rcar/adg.c index 2a5b3a2..b123734 100644 --- 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 rsnd_priv *priv, 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;
participants (3)
-
Geert Uytterhoeven -
Kuninori Morimoto -
Mark Brown