From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Qu Wenruo , Nikolay Borisov , David Sterba , Ben Hutchings , Sasha Levin Subject: [PATCH 4.14 030/146] btrfs: Check if item pointer overlaps with the item itself Date: Tue, 4 Dec 2018 11:48:36 +0100 Message-Id: <20181204103728.071424574@linuxfoundation.org> In-Reply-To: <20181204103726.750894136@linuxfoundation.org> References: <20181204103726.750894136@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ commit 7f43d4affb2a254d421ab20b0cf65ac2569909fb upstream. Function check_leaf() checks if any item pointer points outside of the leaf, but it doesn't check if the pointer overlaps with the item itself. Normally only the last item may be the victim, but adding such check is never a bad idea anyway. Signed-off-by: Qu Wenruo Reviewed-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Ben Hutchings Signed-off-by: Sasha Levin --- fs/btrfs/disk-io.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 4a1e63df1183..da7b2039e4cb 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -644,6 +644,13 @@ static noinline int check_leaf(struct btrfs_root *root, return -EUCLEAN; } + /* Also check if the item pointer overlaps with btrfs item. */ + if (btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item) > + btrfs_item_ptr_offset(leaf, slot)) { + CORRUPT("slot overlap with its data", leaf, root, slot); + return -EUCLEAN; + } + prev_key.objectid = key.objectid; prev_key.type = key.type; prev_key.offset = key.offset; -- 2.17.1