[PATCH AUTOSEL 4.19 08/12] ASoC: soc-pcm: Add NULL check in BE reparenting

[Sasha Levin]

From: Srinivasa Rao Mandadapu <quic_srivasam@xxxxxxxxxxx>

[ Upstream commit db8f91d424fe0ea6db337aca8bc05908bbce1498 ]

Add NULL check in dpcm_be_reparent API, to handle
kernel NULL pointer dereference error.
The issue occurred in fuzzing test.

Signed-off-by: Srinivasa Rao Mandadapu <quic_srivasam@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/1669098673-29703-1-git-send-email-quic_srivasam@xxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 sound/soc/soc-pcm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index c03b653bf6ff..1fabb285b016 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -1266,6 +1266,8 @@ static void dpcm_be_reparent(struct snd_soc_pcm_runtime *fe,
 		return;
 
 	be_substream = snd_soc_dpcm_get_substream(be, stream);
+	if (!be_substream)
+		return;
 
 	list_for_each_entry(dpcm, &be->dpcm[stream].fe_clients, list_fe) {
 		if (dpcm->fe == fe)
-- 
2.35.1