Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Mark Brown <broonie@kernel.org>
Subject: [PATCH 3.18 50/85] ASoC: dapm: delete dapm_kcontrol_data paths list before freeing it
Date:   Sun,  1 Jul 2018 18:02:08 +0200
Message-Id: <20180701153124.346157749@linuxfoundation.org>
In-Reply-To: <20180701153122.365061142@linuxfoundation.org>
References: <20180701153122.365061142@linuxfoundation.org>
User-Agent: quilt/0.65
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

commit ff2faf1289c1f81b5b26b9451dd1c2006aac8db8 upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -254,6 +254,8 @@ static int dapm_kcontrol_data_alloc(stru
 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);
 }