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

[ Upstream commit 1b41beaa7a58467505ec3023af8aad74f878b888 ]

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: 89cdb224f2ab ("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 5c218a39ca20149a2abd4fb192f90d378bb44f7f..57adcefce043eb1617bc35278f9c6772d04967f4 100644 (file)
--- a/sound/soc/intel/boards/sof_es8336.c
+++ b/sound/soc/intel/boards/sof_es8336.c
@@ -782,7 +782,7 @@ 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);