From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753673AbaKZX6Y (ORCPT ); Wed, 26 Nov 2014 18:58:24 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:34659 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753311AbaKZX6W (ORCPT ); Wed, 26 Nov 2014 18:58:22 -0500 From: Sasha Levin To: mingo@kernel.org, akpm@linux-foundation.org, torvalds@linux-foundation.org Cc: linux-kernel@vger.kernel.org, Sasha Levin Subject: [RFC v2 2/2] fs: correctly check for signed integer overflow in vfs_fallocate Date: Wed, 26 Nov 2014 18:58:02 -0500 Message-Id: <1417046282-31825-2-git-send-email-sasha.levin@oracle.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1417046282-31825-1-git-send-email-sasha.levin@oracle.com> References: <1417046282-31825-1-git-send-email-sasha.levin@oracle.com> X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Both "offset" and "len" are signed integers who's addition may overflow and trigger undefined behaviour. Signed-off-by: Sasha Levin --- fs/open.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/open.c b/fs/open.c index 813be03..33d5cae 100644 --- a/fs/open.c +++ b/fs/open.c @@ -287,7 +287,8 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) return -ENODEV; /* Check for wrap through zero too */ - if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) + if (check_add_overflow(offset, len) || + (offset + len) > inode->i_sb->s_maxbytes) return -EFBIG; if (!file->f_op->fallocate) -- 1.7.10.4