From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752906AbcFFOfi (ORCPT ); Mon, 6 Jun 2016 10:35:38 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:58883 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752505AbcFFOaH (ORCPT ); Mon, 6 Jun 2016 10:30:07 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Adam Borowski , David Sterba Subject: [PATCH 4.5 120/128] btrfs: fix int32 overflow in shrink_delalloc(). Date: Sun, 5 Jun 2016 15:24:35 -0700 Message-Id: <20160605222325.050814523@linuxfoundation.org> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20160605222321.183131188@linuxfoundation.org> References: <20160605222321.183131188@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Adam Borowski commit 8eb0dfdbda3f56bf7d248ed87fcc383df114ecbb upstream. UBSAN: Undefined behaviour in fs/btrfs/extent-tree.c:4623:21 signed integer overflow: 10808 * 262144 cannot be represented in type 'int [8]' If 8192<=items<16384, we request a writeback of an insane number of pages which is benign (everything will be written). But if items>=16384, the space reservation won't be enough. Signed-off-by: Adam Borowski Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/extent-tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4620,7 +4620,7 @@ static void shrink_delalloc(struct btrfs /* Calc the number of the pages we need flush for space reservation */ items = calc_reclaim_items_nr(root, to_reclaim); - to_reclaim = items * EXTENT_SIZE_PER_ITEM; + to_reclaim = (u64)items * EXTENT_SIZE_PER_ITEM; trans = (struct btrfs_trans_handle *)current->journal_info; block_rsv = &root->fs_info->delalloc_block_rsv;