From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:45732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726762AbeJKXNP (ORCPT ); Thu, 11 Oct 2018 19:13:15 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joe Thornber , Mike Snitzer Subject: [PATCH 4.14 19/45] dm cache metadata: ignore hints array being too small during resize Date: Thu, 11 Oct 2018 17:39:46 +0200 Message-Id: <20181011152509.687556424@linuxfoundation.org> In-Reply-To: <20181011152508.885515042@linuxfoundation.org> References: <20181011152508.885515042@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joe Thornber commit 4561ffca88c546f96367f94b8f1e4715a9c62314 upstream. Commit fd2fa9541 ("dm cache metadata: save in-core policy_hint_size to on-disk superblock") enabled previously written policy hints to be used after a cache is reactivated. But in doing so the cache metadata's hint array was left exposed to out of bounds access because on resize the metadata's on-disk hint array wasn't ever extended. Fix this by ignoring that there are no on-disk hints associated with the newly added cache blocks. An expanded on-disk hint array is later rewritten upon the next clean shutdown of the cache. Fixes: fd2fa9541 ("dm cache metadata: save in-core policy_hint_size to on-disk superblock") Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-cache-metadata.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -1454,8 +1454,8 @@ static int __load_mappings(struct dm_cac if (hints_valid) { r = dm_array_cursor_next(&cmd->hint_cursor); if (r) { - DMERR("dm_array_cursor_next for hint failed"); - goto out; + dm_array_cursor_end(&cmd->hint_cursor); + hints_valid = false; } }