| Message ID | 20240930101216.23723-1-chenqiuji666@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ASoC: codecs: Fix atomicity violation in snd_soc_component_get_drvdata() | expand |
On Mon, 30 Sep 2024 18:12:16 +0800, Qiu-ji Chen wrote: > 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. > > [...] Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next Thanks! [1/1] ASoC: codecs: Fix atomicity violation in snd_soc_component_get_drvdata() commit: 1157733344651ca505e259d6554591ff156922fa All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark
diff --git a/sound/soc/codecs/da7219.c b/sound/soc/codecs/da7219.c index 311ea7918b31..e2da3e317b5a 100644 --- a/sound/soc/codecs/da7219.c +++ b/sound/soc/codecs/da7219.c @@ -1167,17 +1167,20 @@ static int da7219_set_dai_sysclk(struct snd_soc_dai *codec_dai, 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,
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> --- sound/soc/codecs/da7219.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)