[PATCH 2/4] ASoC: core: Check for rtd == NULL in snd_soc_remove_pcm_runtime()

[Peter Ujfalusi <peter.ujfalusi@linux.intel.com>]

snd_soc_remove_pcm_runtime() might be called with rtd == NULL which will
leads to null pointer dereference.
This was reproduced with topology loading and marking a link as ignore
due to missing hardware component on the system.
On module removal the soc_tplg_remove_link() would call
snd_soc_remove_pcm_runtime() with rtd == NULL since the link was ignored,
no runtime was created.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
---
 sound/soc/soc-core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index cfafdabcdc88..1ffabac1fb6b 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -1139,6 +1139,9 @@ static int snd_soc_compensate_channel_connection_map(struct snd_soc_card *card,
 void snd_soc_remove_pcm_runtime(struct snd_soc_card *card,
 				struct snd_soc_pcm_runtime *rtd)
 {
+	if (!rtd)
+		return;
+
 	lockdep_assert_held(&client_mutex);
 
 	/*
-- 
2.49.0