From 307ab2a99d190d3a7949258b8551b66887ce8cf4 Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@dell.com>
Date: Sun, 5 Nov 2017 21:34:34 -0600
Subject: [PATCH] platform/x86: dell-smbios-wmi: release mutex lock on WMI call failure
Git-commit: 307ab2a99d190d3a7949258b8551b66887ce8cf4
Patch-mainline: v4.15-rc1
References: FATE#325842

Unbound devices may race with calling this function causing the mutex
to stay locked.  This failure mode should have released the mutex too.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/platform/x86/dell-smbios-wmi.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/platform/x86/dell-smbios-wmi.c
+++ b/drivers/platform/x86/dell-smbios-wmi.c
@@ -91,8 +91,10 @@ int dell_smbios_wmi_call(struct calling_
 
 	mutex_lock(&call_mutex);
 	priv = get_first_smbios_priv();
-	if (!priv)
-		return -ENODEV;
+	if (!priv) {
+		ret = -ENODEV;
+		goto out_wmi_call;
+	}
 
 	size = sizeof(struct calling_interface_buffer);
 	difference = priv->req_buf_size - sizeof(u64) - size;
@@ -101,6 +103,7 @@ int dell_smbios_wmi_call(struct calling_
 	memcpy(&priv->buf->std, buffer, size);
 	ret = run_smbios_call(priv->wdev);
 	memcpy(buffer, &priv->buf->std, size);
+out_wmi_call:
 	mutex_unlock(&call_mutex);
 
 	return ret;