[PATCH v5 1/4] ASoC: qcom: q6apm: clear g_apm on driver removal

[Ajay Kumar Nandam <ajay.nandam@oss.qualcomm.com>]

The global g_apm pointer is set during apm_probe() but never cleared
in apm_remove(). After the driver is removed the devm-managed struct
q6apm is freed, leaving g_apm dangling. A subsequent call to
q6apm_is_adsp_ready() dereferences the freed pointer.

Clear g_apm in apm_remove() before the component is unregistered so
that q6apm_is_adsp_ready() returns false instead of triggering a
use-after-free.

Fixes: 5477518b8a0e ("ASoC: qdsp6: audioreach: add q6apm support")
Signed-off-by: Ajay Kumar Nandam <ajay.nandam@oss.qualcomm.com>
---
 sound/soc/qcom/qdsp6/q6apm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/soc/qcom/qdsp6/q6apm.c b/sound/soc/qcom/qdsp6/q6apm.c
index 641d6d243229..12c6dfe4c58e 100644
--- a/sound/soc/qcom/qdsp6/q6apm.c
+++ b/sound/soc/qcom/qdsp6/q6apm.c
@@ -894,6 +894,7 @@ static int apm_probe(gpr_device_t *gdev)
 
 static void apm_remove(gpr_device_t *gdev)
 {
+	g_apm = NULL;
 	of_platform_depopulate(&gdev->dev);
 	snd_soc_unregister_component(&gdev->dev);
 }

-- 
2.34.1