From: Jonghwan Choi <jhbird.choi@samsung.com>
Date: Sat, 14 Jan 2012 02:06:03 +0000 (+0900)
Subject: driver-core: Fix possible null reference in subsys_interface_unregister
X-Git-Tag: firefly_0821_release~3680^2~3348^2~57
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=2b31594a9523449b168946725689d039c80204de;p=firefly-linux-kernel-4.4.55.git

driver-core: Fix possible null reference in subsys_interface_unregister

Check if the sif is not NULL before de-referencing it

Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 99dc5921e1dd..4ddb38b696fe 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -1193,13 +1193,15 @@ EXPORT_SYMBOL_GPL(subsys_interface_register);
 
 void subsys_interface_unregister(struct subsys_interface *sif)
 {
-	struct bus_type *subsys = sif->subsys;
+	struct bus_type *subsys;
 	struct subsys_dev_iter iter;
 	struct device *dev;
 
-	if (!sif)
+	if (!sif || !sif->subsys)
 		return;
 
+	subsys = sif->subsys;
+
 	mutex_lock(&subsys->p->mutex);
 	list_del_init(&sif->node);
 	if (sif->remove_dev) {