[PATCH] media: pvrusb2: fix null-ptr-deref in class_unregister()

[Kefeng Wang]

The class_ptr will be NULL if pvr2_sysfs_class_create() fails
in pvr_init(), when call pvr2_sysfs_class_destroy(), it will
lead to null-ptr-deref, fix it.

Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
 drivers/media/usb/pvrusb2/pvrusb2-sysfs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/pvrusb2/pvrusb2-sysfs.c b/drivers/media/usb/pvrusb2/pvrusb2-sysfs.c
index 7bc6d090358e..b6c6b314fadc 100644
--- a/drivers/media/usb/pvrusb2/pvrusb2-sysfs.c
+++ b/drivers/media/usb/pvrusb2/pvrusb2-sysfs.c
@@ -802,7 +802,8 @@ struct pvr2_sysfs_class *pvr2_sysfs_class_create(void)
 void pvr2_sysfs_class_destroy(struct pvr2_sysfs_class *clp)
 {
 	pvr2_sysfs_trace("Unregistering pvr2_sysfs_class id=%p", clp);
-	class_unregister(&clp->class);
+	if (clp)
+		class_unregister(&clp->class);
 }
 
 
-- 
2.20.1