nvmet: filter newlines from user input

We should avoid consuming the newlines in traddr, trsvcid and
device_path. Add minimal processing to make sure they are gone.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/nvme/target/configfs.c

@@ -137,8 +137,10 @@ static ssize_t nvmet_addr_traddr_store(struct config_item *item,
 		pr_err("Disable the address before modifying\n");
 		return -EACCES;
 	}
-	return snprintf(port->disc_addr.traddr,
-			sizeof(port->disc_addr.traddr), "%s", page);
+
+	if (sscanf(page, "%s\n", port->disc_addr.traddr) != 1)
+		return -EINVAL;
+	return count;
 }
 
 CONFIGFS_ATTR(nvmet_, addr_traddr);
@@ -208,8 +210,10 @@ static ssize_t nvmet_addr_trsvcid_store(struct config_item *item,
 		pr_err("Disable the address before modifying\n");
 		return -EACCES;
 	}
-	return snprintf(port->disc_addr.trsvcid,
-			sizeof(port->disc_addr.trsvcid), "%s", page);
+
+	if (sscanf(page, "%s\n", port->disc_addr.trsvcid) != 1)
+		return -EINVAL;
+	return count;
 }
 
 CONFIGFS_ATTR(nvmet_, addr_trsvcid);
@@ -288,7 +292,7 @@ static ssize_t nvmet_ns_device_path_store(struct config_item *item,
 	kfree(ns->device_path);
 
 	ret = -ENOMEM;
-	ns->device_path = kstrdup(page, GFP_KERNEL);
+	ns->device_path = kstrndup(page, strcspn(page, "\n"), GFP_KERNEL);
 	if (!ns->device_path)
 		goto out_unlock;