2019-01-04 21:56:53

by Yizhuo Zhai

[permalink] [raw]

Subject: [PATCH] ASoC: rt298: Variable "val" and "buf" in rt298_jack_detect() could be uninitialized

---

In function rt298_jack_detect(), local variable "val" and "buf"
are supposed to get initialized by regmap_read(). However, they
could be leave uninitialized if regmap_read() returns -EINVAL.
Those two variables are used in control flow or update the argument,
which could lead to undefined behavior and thus unsafe.

Signed-off-by: Yizhuo <[email protected]>
---
sound/soc/codecs/rt298.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/sound/soc/codecs/rt298.c b/sound/soc/codecs/rt298.c
index ce963768449f..7f74349c17f3 100644
--- a/sound/soc/codecs/rt298.c
+++ b/sound/soc/codecs/rt298.c
@@ -223,6 +223,7 @@ static int rt298_jack_detect(struct rt298_priv *rt298, bool *hp, bool *mic)
{
struct snd_soc_dapm_context *dapm;
unsigned int val, buf;
+ int ret = 0;

*hp = false;
*mic = false;
@@ -233,7 +234,10 @@ static int rt298_jack_detect(struct rt298_priv *rt298, bool *hp, bool *mic)
dapm = snd_soc_codec_get_dapm(rt298->codec);

if (rt298->pdata.cbj_en) {
- regmap_read(rt298->regmap, RT298_GET_HP_SENSE, &buf);
+ ret = regmap_read(rt298->regmap, RT298_GET_HP_SENSE, &buf);
+ if (ret)
+ return ret;
+
*hp = buf & 0x80000000;
if (*hp == rt298->is_hp_in)
return -1;
@@ -260,16 +264,19 @@ static int rt298_jack_detect(struct rt298_priv *rt298, bool *hp, bool *mic)
regmap_update_bits(rt298->regmap,
RT298_CBJ_CTRL1, 0xfcc0, 0xd400);
msleep(300);
- regmap_read(rt298->regmap, RT298_CBJ_CTRL2, &val);
-
+ ret = regmap_read(rt298->regmap, RT298_CBJ_CTRL2, &val);
+ if (ret)
+ return ret;
if (0x0070 == (val & 0x0070)) {
*mic = true;
} else {
regmap_update_bits(rt298->regmap,
RT298_CBJ_CTRL1, 0xfcc0, 0xe400);
msleep(300);
- regmap_read(rt298->regmap,
+ ret = regmap_read(rt298->regmap,
RT298_CBJ_CTRL2, &val);
+ if (ret)
+ return ret;
if (0x0070 == (val & 0x0070))
*mic = true;
else
@@ -285,9 +292,14 @@ static int rt298_jack_detect(struct rt298_priv *rt298, bool *hp, bool *mic)
RT298_CBJ_CTRL1, 0x0400, 0x0000);
}
} else {
- regmap_read(rt298->regmap, RT298_GET_HP_SENSE, &buf);
+ ret = regmap_read(rt298->regmap, RT298_GET_HP_SENSE, &buf);
+ if (ret)
+ return ret;
+
*hp = buf & 0x80000000;
- regmap_read(rt298->regmap, RT298_GET_MIC1_SENSE, &buf);
+ ret = regmap_read(rt298->regmap, RT298_GET_MIC1_SENSE, &buf);
+ if (ret)
+ return ret;
*mic = buf & 0x80000000;
}

--
2.17.1

2019-01-07 18:51:35

by Mark Brown

[permalink] [raw]

Subject: Re: [PATCH] ASoC: rt298: Variable "val" and "buf" in rt298_jack_detect() could be uninitialized

---

On Fri, Jan 04, 2019 at 01:52:53PM -0800, Yizhuo wrote:

> {
> struct snd_soc_dapm_context *dapm;
> unsigned int val, buf;
> + int ret = 0;

It's bad practice to just initailize like this without a reason - it
tends to just mask actual cases where we miss error handling by ensuring
that it's always initialized.

> if (0x0070 == (val & 0x0070)) {
> *mic = true;
> } else {
> regmap_update_bits(rt298->regmap,
> RT298_CBJ_CTRL1, 0xfcc0, 0xe400);
> msleep(300);
> - regmap_read(rt298->regmap,
> + ret = regmap_read(rt298->regmap,
> RT298_CBJ_CTRL2, &val);
> + if (ret)
> + return ret;

We've started doing some writes to the device (which you've not added
checks for) here but then if the read fails we just bomb out with an
error code - are you sure that none of the writes need to be reverted?

---

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