4.19-stable review patch. If anyone has any objections, please let me know.
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From: Qiu-ji Chen chenqiuji666@gmail.com
commit 1157733344651ca505e259d6554591ff156922fa upstream.
An atomicity violation occurs when the validity of the variables da7219->clk_src and da7219->mclk_rate is being assessed. Since the entire assessment is not protected by a lock, the da7219 variable might still be in flux during the assessment, rendering this check invalid.
To fix this issue, we recommend adding a lock before the block if ((da7219->clk_src == clk_id) && (da7219->mclk_rate == freq)) so that the legitimacy check for da7219->clk_src and da7219->mclk_rate is protected by the lock, ensuring the validity of the check.
This possible bug is found by an experimental static analysis tool developed by our team. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including data races and atomicity violations.
Fixes: 6d817c0e9fd7 ("ASoC: codecs: Add da7219 codec driver") Cc: stable@vger.kernel.org Signed-off-by: Qiu-ji Chen chenqiuji666@gmail.com Link: https://patch.msgid.link/20240930101216.23723-1-chenqiuji666@gmail.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- sound/soc/codecs/da7219.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
--- a/sound/soc/codecs/da7219.c +++ b/sound/soc/codecs/da7219.c @@ -1164,17 +1164,20 @@ static int da7219_set_dai_sysclk(struct struct da7219_priv *da7219 = snd_soc_component_get_drvdata(component); int ret = 0;
- if ((da7219->clk_src == clk_id) && (da7219->mclk_rate == freq)) + mutex_lock(&da7219->pll_lock); + + if ((da7219->clk_src == clk_id) && (da7219->mclk_rate == freq)) { + mutex_unlock(&da7219->pll_lock); return 0; + }
if ((freq < 2000000) || (freq > 54000000)) { + mutex_unlock(&da7219->pll_lock); dev_err(codec_dai->dev, "Unsupported MCLK value %d\n", freq); return -EINVAL; }
- mutex_lock(&da7219->pll_lock); - switch (clk_id) { case DA7219_CLKSRC_MCLK_SQR: snd_soc_component_update_bits(component, DA7219_PLL_CTRL,