ALSA: rockchip_i2s: fix a possible divide-by-zero bug in rockchip_i2s_hw_params()

The variable bclk_rate is checked in:
  if (bclk_rate && mclk_rate % bclk_rate)

This indicates that bclk_rate can be zero.
If so, a divide-by-zero bug will occur:
  div_bclk = mclk_rate / bclk_rate;

To fix this possible bug, the function returns -EINVAL when bclk_rate is
zero.

Signed-off-by: Tuo Li <tuoli96@outlook.com>
Link: https://lore.kernel.org/r/TY2PR04MB4029799E60A5BCAAD5B7B5BBB8280@TY2PR04MB4029.apcprd04.prod.outlook.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/rockchip/rockchip_i2s.c b/sound/soc/rockchip/rockchip_i2s.c
index d143875..5932996 100644 (file)
--- a/sound/soc/rockchip/rockchip_i2s.c
+++ b/sound/soc/rockchip/rockchip_i2s.c
@@ -279,7 +279,7 @@ static int rockchip_i2s_hw_params(struct snd_pcm_substream *substream,
        if (i2s->is_master_mode) {
                mclk_rate = clk_get_rate(i2s->mclk);
                bclk_rate = 2 * 32 * params_rate(params);
-               if (bclk_rate && mclk_rate % bclk_rate)
+               if (bclk_rate == 0 || mclk_rate % bclk_rate)
                        return -EINVAL;
 
                div_bclk = mclk_rate / bclk_rate;