From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f47.google.com ([74.125.82.47]:53218 "EHLO mail-wg0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754221AbaAUXgq (ORCPT ); Tue, 21 Jan 2014 18:36:46 -0500 Received: by mail-wg0-f47.google.com with SMTP id m15so8462845wgh.26 for ; Tue, 21 Jan 2014 15:36:45 -0800 (PST) From: Filipe David Borba Manana To: linux-btrfs@vger.kernel.org Cc: Filipe David Borba Manana Subject: [PATCH] Btrfs: fix snprintf usage by send's gen_unique_name Date: Tue, 21 Jan 2014 23:36:38 +0000 Message-Id: <1390347398-6490-1-git-send-email-fdmanana@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: The buffer size argument passed to snprintf must account for the trailing null byte added by snprintf, and it returns a value >= then sizeof(buffer) when the string can't fit in the buffer. Since our buffer has a size of 64 characters, and the maximum orphan name we can generate is 63 characters wide, we must pass 64 as the buffer size to snprintf, and not 63. Signed-off-by: Filipe David Borba Manana --- fs/btrfs/send.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 84aed2f..27edc5e 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -1336,7 +1336,7 @@ static int gen_unique_name(struct send_ctx *sctx, return -ENOMEM; while (1) { - len = snprintf(tmp, sizeof(tmp) - 1, "o%llu-%llu-%llu", + len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu", ino, gen, idx); if (len >= sizeof(tmp)) { /* should really not happen */ -- 1.7.9.5