From: Guennadi Liakhovetski <[email protected]> [ Upstream commit 52abe6cc1866ac3d54612f5d80563e6608c0ddfc ]
rmmod/modprobe tests expose a kernel oops when accessing the dai driver pointer. This comes from the topology design which operates in multiple passes. Each object removal happens at a specific iteration, and the code checks for the iteration (order) number after the memory containing the order was freed. Fix this be clearing a reference to the dai driver and check its validity to avoid dereferences. Signed-off-by: Guennadi Liakhovetski <[email protected]> Signed-off-by: Pierre-Louis Bossart <[email protected]> Signed-off-by: Mark Brown <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- sound/soc/soc-core.c | 2 +- sound/soc/soc-topology.c | 5 +++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index 2d49492d6069..c8c6c5a6de8f 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -951,7 +951,7 @@ static void soc_remove_dai(struct snd_soc_dai *dai, int order) { int err; - if (!dai || !dai->probed || + if (!dai || !dai->probed || !dai->driver || dai->driver->remove_order != order) return; diff --git a/sound/soc/soc-topology.c b/sound/soc/soc-topology.c index 045ef136903d..fc79ec6927e3 100644 --- a/sound/soc/soc-topology.c +++ b/sound/soc/soc-topology.c @@ -502,6 +502,7 @@ static void remove_dai(struct snd_soc_component *comp, { struct snd_soc_dai_driver *dai_drv = container_of(dobj, struct snd_soc_dai_driver, dobj); + struct snd_soc_dai *dai; if (pass != SOC_TPLG_PASS_PCM_DAI) return; @@ -509,6 +510,10 @@ static void remove_dai(struct snd_soc_component *comp, if (dobj->ops && dobj->ops->dai_unload) dobj->ops->dai_unload(comp, dobj); + list_for_each_entry(dai, &comp->dai_list, list) + if (dai->driver == dai_drv) + dai->driver = NULL; + kfree(dai_drv->name); list_del(&dobj->list); kfree(dai_drv); -- 2.19.1
