From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1F15C433EF for ; Wed, 15 Jun 2022 03:54:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353863AbiFODyu (ORCPT ); Tue, 14 Jun 2022 23:54:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353866AbiFODyJ (ORCPT ); Tue, 14 Jun 2022 23:54:09 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 029B4D95; Tue, 14 Jun 2022 20:53:37 -0700 (PDT) Received: from dggpeml500021.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4LNBGt1SmHzDrJQ; Wed, 15 Jun 2022 11:53:10 +0800 (CST) Received: from huawei.com (10.175.127.227) by dggpeml500021.china.huawei.com (7.185.36.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 15 Jun 2022 11:53:35 +0800 From: Baokun Li To: CC: , , , , , , , , , , Subject: [PATCH v2 1/4] ext4: add EXT4_INODE_HAVE_XATTR_SPACE macro in xattr.h Date: Wed, 15 Jun 2022 12:06:27 +0800 Message-ID: <20220615040630.808783-2-libaokun1@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220615040630.808783-1-libaokun1@huawei.com> References: <20220615040630.808783-1-libaokun1@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpeml500021.china.huawei.com (7.185.36.21) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org When adding an xattr to an inode, we must ensure that the inode_size is not less than EXT4_GOOD_OLD_INODE_SIZE + extra_isize + pad. Otherwise, the end position may be greater than the start position, resulting in UAF. Signed-off-by: Baokun Li --- fs/ext4/xattr.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h index 77efb9a627ad..3fd17b25596f 100644 --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -95,6 +95,19 @@ struct ext4_xattr_entry { #define EXT4_ZERO_XATTR_VALUE ((void *)-1) +/* + * If we want to add an xattr to the inode, we should make sure that + * i_extra_isize is not 0 and that the inode size is not less than + * EXT4_GOOD_OLD_INODE_SIZE + extra_isize + pad. + * EXT4_GOOD_OLD_INODE_SIZE extra_isize header entry pad data + * |--------------------------|------------|------|---------|---|-------| + */ +#define EXT4_INODE_HAVE_XATTR_SPACE(inode) \ + ((EXT4_I(inode)->i_extra_isize != 0) && \ + (EXT4_GOOD_OLD_INODE_SIZE + EXT4_I(inode)->i_extra_isize + \ + sizeof(struct ext4_xattr_ibody_header) + EXT4_XATTR_PAD <= \ + EXT4_INODE_SIZE((inode)->i_sb))) + struct ext4_xattr_info { const char *name; const void *value; -- 2.31.1