From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:35470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932178AbcGKLQe (ORCPT ); Mon, 11 Jul 2016 07:16:34 -0400 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 232762020F for ; Mon, 11 Jul 2016 11:16:33 +0000 (UTC) Received: from debian3.lan (bl12-226-64.dsl.telepac.pt [85.245.226.64]) (using TLSv1.2 with cipher AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 02F2C201F4 for ; Mon, 11 Jul 2016 11:16:31 +0000 (UTC) From: fdmanana@kernel.org To: linux-btrfs@vger.kernel.org Subject: [PATCH 7/7] Btrfs: send, avoid incorrect leaf accesses when sending utimes operations Date: Sat, 2 Jul 2016 13:31:03 +0100 Message-Id: <1467462663-14443-1-git-send-email-fdmanana@kernel.org> Sender: linux-btrfs-owner@vger.kernel.org List-ID: From: Filipe Manana The caller of send_utimes() is supposed to be sure that the inode number it passes to this function does actually exists in the send snapshot. However due to logic/algorithm bugs (such as the one fixed by the patch titled "Btrfs: send, fix invalid leaf accesses due to incorrect utimes operations"), this might not be the case and when that happens it makes send_utimes() access use an unrelated leaf item as the target inode item or access beyond a leaf's boundaries (when the leaf is full and path->slots[0] matches the number of items in the leaf). So if the call to btrfs_search_slot() done by send_utimes() does not find the inode item, just make sure send_utimes() returns -ENOENT and does not silently accesses unrelated leaf items or does invalid leaf accesses, also allowing us to easialy and deterministically catch such algorithmic/logic bugs. Signed-off-by: Filipe Manana --- fs/btrfs/send.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 8b65396..2db8dc8 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -2502,6 +2502,8 @@ verbose_printk("btrfs: send_utimes %llu\n", ino); key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0); + if (ret > 0) + ret = -ENOENT; if (ret < 0) goto out; -- 2.7.0.rc3