ASoC: sof_es8336: fix possible use-after-free in sof_es8336_remove()

[ Upstream commit f8ca855a570a1dbd73c7c0eaf37a93acff0b7e5e ]

sof_es8336_remove() calls cancel_delayed_work(). However, that
function does not wait until the work function finishes. This
means that the callback function may still be running after
the driver's remove function has finished, which would result
in a use-after-free.

Fix by calling cancel_delayed_work_sync(), which ensures that
the work is properly cancelled, no longer running, and unable
to re-schedule itself.

Fixes: 1b9cb679e4e5 ("ASoC: sof_es8336: reduce pop noise on speaker")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20221205143721.3988988-1-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/sound/soc/intel/boards/sof_es8336.c b/sound/soc/intel/boards/sof_es8336.c
index 70713e4b07dc108572ec53a721adbf8ffe1d20bb..773e5d1d87d460362bb7d440544fe764cac2ad08 100644 (file)
--- a/sound/soc/intel/boards/sof_es8336.c
+++ b/sound/soc/intel/boards/sof_es8336.c
@@ -783,7 +783,7 @@ static int sof_es8336_remove(struct platform_device *pdev)
        struct snd_soc_card *card = platform_get_drvdata(pdev);
        struct sof_es8336_private *priv = snd_soc_card_get_drvdata(card);
 
-       cancel_delayed_work(&priv->pcm_pop_work);
+       cancel_delayed_work_sync(&priv->pcm_pop_work);
        gpiod_put(priv->gpio_speakers);
        device_remove_software_node(priv->codec_dev);
        put_device(priv->codec_dev);