From d40f6d71da81deb66c4fa54b46e22977cdb8b451 Mon Sep 17 00:00:00 2001
From: Jeff Dike <jdike@addtoit.com>
Date: Thu, 29 Mar 2007 01:20:28 -0700
Subject: [PATCH] uml: fix device unplug crash

Fix a NULL dereference when unplugging a device.  The default value of
err_msg wants to be "" in case the driver doesn't modify it.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 178b2ef..65ad293 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -615,6 +615,9 @@ void mconsole_remove(struct mc_request *req)
 	err_msg = NULL;
 	err = (*dev->remove)(n, &err_msg);
 	switch(err){
+	case 0:
+		err_msg = "";
+		break;
 	case -ENODEV:
 		if(err_msg == NULL)
 			err_msg = "Device doesn't exist";
-- 
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