ASoC: codecs: tx-macro: Fix for KASAN: slab-out-of-bounds

Commit Message

Ravulapati Vishnu Vardhan Rao March 3, 2023, 12:57 p.m. UTC

From: visr <[e-mail]>

When we run syzkaller we get below Out of Bound.
"KASAN: slab-out-of-bounds Read in regcache_flat_read"

Below is the backtrace of the issue:

dump_backtrace+0x0/0x4c8
show_stack+0x34/0x44
dump_stack_lvl+0xd8/0x118
print_address_description+0x30/0x2d8
kasan_report+0x158/0x198
__asan_report_load4_noabort+0x44/0x50
regcache_flat_read+0x10c/0x110
regcache_read+0xf4/0x180
_regmap_read+0xc4/0x278
_regmap_update_bits+0x130/0x290
regmap_update_bits_base+0xc0/0x15c
snd_soc_component_update_bits+0xa8/0x22c
snd_soc_component_write_field+0x68/0xd4
tx_macro_digital_mute+0xec/0x140

Actually There is no need to have decimator with 32 bits.
By limiting the variable with short type u8 issue is resolved.

Signed-off-by: RAVULAPATI VISHNUVARDHAN RAO <[e-mail]>
---
 sound/soc/codecs/lpass-tx-macro.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

Comments

Ravulapati Vishnu Vardhan Rao March 3, 2023, 5:32 p.m. UTC | #1

On 3/3/2023 7:45 PM, Srinivas Kandagatla wrote:
>
>
> On 03/03/2023 12:57, Ravulapati Vishnu Vardhan Rao wrote:
>> @@ -1064,9 +1064,10 @@ static int tx_macro_hw_params(struct 
>> snd_pcm_substream *substream,
>>                     struct snd_soc_dai *dai)
>>   {
>>       struct snd_soc_component *component = dai->component;
>> -    u32 decimator, sample_rate;
>> +    u32 sample_rate;
>>       int tx_fs_rate;
>>       struct tx_macro *tx = snd_soc_component_get_drvdata(component);
>> +    u8 decimator = 0;
> Minor nit, any reason why decimator is intialized as part of this change.
>
> --srini
Will Remove that..Thanks for review

Patch

diff --git a/sound/soc/codecs/lpass-tx-macro.c b/sound/soc/codecs/lpass-tx-macro.c
index bf27bdd5be20..73014fa6e4b8 100644
--- a/sound/soc/codecs/lpass-tx-macro.c
+++ b/sound/soc/codecs/lpass-tx-macro.c
@@ -242,7 +242,7 @@  enum {
 
 struct tx_mute_work {
 	struct tx_macro *tx;
-	u32 decimator;
+	u8 decimator;
 	struct delayed_work dwork;
 };
 
@@ -635,7 +635,7 @@  static int tx_macro_mclk_enable(struct tx_macro *tx,
 	return 0;
 }
 
-static bool is_amic_enabled(struct snd_soc_component *component, int decimator)
+static bool is_amic_enabled(struct snd_soc_component *component, u8 decimator)
 {
 	u16 adc_mux_reg, adc_reg, adc_n;
 
@@ -849,7 +849,7 @@  static int tx_macro_enable_dec(struct snd_soc_dapm_widget *w,
 			       struct snd_kcontrol *kcontrol, int event)
 {
 	struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
-	unsigned int decimator;
+	u8 decimator;
 	u16 tx_vol_ctl_reg, dec_cfg_reg, hpf_gate_reg, tx_gain_ctl_reg;
 	u8 hpf_cut_off_freq;
 	int hpf_delay = TX_MACRO_DMIC_HPF_DELAY_MS;
@@ -1064,9 +1064,10 @@  static int tx_macro_hw_params(struct snd_pcm_substream *substream,
 			      struct snd_soc_dai *dai)
 {
 	struct snd_soc_component *component = dai->component;
-	u32 decimator, sample_rate;
+	u32 sample_rate;
 	int tx_fs_rate;
 	struct tx_macro *tx = snd_soc_component_get_drvdata(component);
+	u8 decimator = 0;
 
 	sample_rate = params_rate(params);
 	switch (sample_rate) {
@@ -1128,7 +1129,7 @@  static int tx_macro_digital_mute(struct snd_soc_dai *dai, int mute, int stream)
 {
 	struct snd_soc_component *component = dai->component;
 	struct tx_macro *tx = snd_soc_component_get_drvdata(component);
-	u16 decimator;
+	u8 decimator;
 
 	/* active decimator not set yet */
 	if (tx->active_decimator[dai->id] == -1)