ALSA: atmel: Fix possible array overflow

The static checker found a possible array overflow in atmel/abdac.c:
  static checker warning: "sound/atmel/abdac.c:373 set_sample_rates()
        error: buffer overflow 'dac->rates' 6 <= 6"

This patch papers over the buggy point, by ensuring that dac->rates[]
update not overflowing the actual array size.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/sound/atmel/abdac.c b/sound/atmel/abdac.c
index 872d59e35ee2..721d8fd45685 100644
--- a/sound/atmel/abdac.c
+++ b/sound/atmel/abdac.c
@@ -357,7 +357,8 @@ static int set_sample_rates(struct atmel_abdac *dac)
                 if (new_rate < 0)
                         break;
                 /* make sure we are below the ABDAC clock */
-                if (new_rate <= clk_get_rate(dac->pclk)) {
+                if (index < MAX_NUM_RATES &&
+                    new_rate <= clk_get_rate(dac->pclk)) {
                         dac->rates[index] = new_rate / 256;
                         index++;
                 }