From ff2faf1289c1f81b5b26b9451dd1c2006aac8db8 Mon Sep 17 00:00:00 2001
From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Date: Mon, 4 Jun 2018 12:13:26 +0100
Subject: [PATCH] ASoC: dapm: delete dapm_kcontrol_data paths list before freeing it
Git-commit: ff2faf1289c1f81b5b26b9451dd1c2006aac8db8
Patch-mainline: v4.18-rc1
References: bsc#1051510

dapm_kcontrol_data is freed as part of dapm_kcontrol_free(), leaving the
paths pointer dangling in the list.

This leads to system crash when we try to unload and reload sound card.
I hit this bug during ADSP crash/reboot test case on Dragon board DB410c.

Without this patch, on SLAB Poisoning enabled build, kernel crashes with
"BUG kmalloc-128 (Tainted: G        W        ): Poison overwritten"

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 sound/soc/soc-dapm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index 1e9a36389667..36a39ba30226 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -433,6 +433,8 @@ static int dapm_kcontrol_data_alloc(struct snd_soc_dapm_widget *widget,
 static void dapm_kcontrol_free(struct snd_kcontrol *kctl)
 {
 	struct dapm_kcontrol_data *data = snd_kcontrol_chip(kctl);
+
+	list_del(&data->paths);
 	kfree(data->wlist);
 	kfree(data);
 }
-- 
2.18.0