[PATCH] driver-core: Fix null reference in subsys_interface_unregister

[jhbird . choi]

From: Jonghwan Choi <jhbird.choi@xxxxxxxxxxx>

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

Signed-off-by: Jonghwan Choi <jhbird.choi@xxxxxxxxxxx>
---
 drivers/base/bus.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 99dc592..4ddb38b 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) {
-- 
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/