mtd: sm_rtl: check kmalloc return value

Because malloc/kzalloc may fail, we should check kmalloc/kzalloc return value
 in sm_create_sysfs_attributes(), mtd/sm_rtl.c and do error handling.
Meanwhile, we should check sm_create_sysfs_attributes return value.

Signed-off-by: Xiaochen Wang <wangxiaochen0@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/sm_ftl.c

@@ -64,12 +64,16 @@ struct attribute_group *sm_create_sysfs_attributes(struct sm_ftl *ftl)
 					SM_SMALL_PAGE - SM_CIS_VENDOR_OFFSET);
 
 	char *vendor = kmalloc(vendor_len, GFP_KERNEL);
+	if (!vendor)
+		goto error1;
 	memcpy(vendor, ftl->cis_buffer + SM_CIS_VENDOR_OFFSET, vendor_len);
 	vendor[vendor_len] = 0;
 
 	/* Initialize sysfs attributes */
 	vendor_attribute =
 		kzalloc(sizeof(struct sm_sysfs_attribute), GFP_KERNEL);
+	if (!vendor_attribute)
+		goto error2;
 
 	sysfs_attr_init(&vendor_attribute->dev_attr.attr);
 
@@ -83,12 +87,24 @@ struct attribute_group *sm_create_sysfs_attributes(struct sm_ftl *ftl)
 	/* Create array of pointers to the attributes */
 	attributes = kzalloc(sizeof(struct attribute *) * (NUM_ATTRIBUTES + 1),
 								GFP_KERNEL);
+	if (!attributes)
+		goto error3;
 	attributes[0] = &vendor_attribute->dev_attr.attr;
 
 	/* Finally create the attribute group */
 	attr_group = kzalloc(sizeof(struct attribute_group), GFP_KERNEL);
+	if (!attr_group)
+		goto error4;
 	attr_group->attrs = attributes;
 	return attr_group;
+error4:
+	kfree(attributes);
+error3:
+	kfree(vendor_attribute);
+error2:
+	kfree(vendor);
+error1:
+	return NULL;
 }
 
 void sm_delete_sysfs_attributes(struct sm_ftl *ftl)
@@ -1178,6 +1194,8 @@ static void sm_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
 	}
 
 	ftl->disk_attributes = sm_create_sysfs_attributes(ftl);
+	if (!ftl->disk_attributes)
+		goto error6;
 	trans->disk_attributes = ftl->disk_attributes;
 
 	sm_printk("Found %d MiB xD/SmartMedia FTL on mtd%d",