From patchwork Mon Oct 7 21:42:58 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zach Brown X-Patchwork-Id: 2999281 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 34C1ABF924 for ; Mon, 7 Oct 2013 21:43:24 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4283D201F9 for ; Mon, 7 Oct 2013 21:43:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 48A2B201EF for ; Mon, 7 Oct 2013 21:43:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753646Ab3JGVnT (ORCPT ); Mon, 7 Oct 2013 17:43:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23870 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753531Ab3JGVnQ (ORCPT ); Mon, 7 Oct 2013 17:43:16 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r97LhGA8000743 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 7 Oct 2013 17:43:16 -0400 Received: from lenny.home.zabbo.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r97LhC9P003268; Mon, 7 Oct 2013 17:43:16 -0400 From: Zach Brown To: linux-btrfs@vger.kernel.org, Eric Sandeen Subject: [PATCH 05/12] btrfs-progs: check link_subvol name base Date: Mon, 7 Oct 2013 14:42:58 -0700 Message-Id: <1381182185-10896-6-git-send-email-zab@redhat.com> In-Reply-To: <1381182185-10896-1-git-send-email-zab@redhat.com> References: <1381182185-10896-1-git-send-email-zab@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In principle, link_subvol() can be given an abitrary string as the name of the saved subvolume. It copies it into a fixed-size stack buffer and then uses it as dirent names without testing its length. This limits its length to BTRFS_NAME_LEN. This was found by static analsys. Signed-off-by: Zach Brown --- btrfs-convert.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/btrfs-convert.c b/btrfs-convert.c index 221dd45..edef1bd 100644 --- a/btrfs-convert.c +++ b/btrfs-convert.c @@ -1428,10 +1428,15 @@ static struct btrfs_root * link_subvol(struct btrfs_root *root, struct btrfs_key key; u64 dirid = btrfs_root_dirid(&root->root_item); u64 index = 2; - char buf[64]; + char buf[BTRFS_NAME_LEN + 1]; /* for snprintf null */ + int len; int i; int ret; + len = strlen(base); + if (len < 1 || len > BTRFS_NAME_LEN) + return NULL; + path = btrfs_alloc_path(); BUG_ON(!path); @@ -1467,18 +1472,22 @@ static struct btrfs_root * link_subvol(struct btrfs_root *root, key.offset = (u64)-1; key.type = BTRFS_ROOT_ITEM_KEY; - strcpy(buf, base); + memcpy(buf, base, len); for (i = 0; i < 1024; i++) { - ret = btrfs_insert_dir_item(trans, root, buf, strlen(buf), + ret = btrfs_insert_dir_item(trans, root, buf, len, dirid, &key, BTRFS_FT_DIR, index); if (ret != -EEXIST) break; - sprintf(buf, "%s%d", base, i); + len = snprintf(buf, ARRAY_SIZE(buf), "%s%d", base, i); + if (len < 1 || len > BTRFS_NAME_LEN) { + ret = -EINVAL; + break; + } } if (ret) goto fail; - btrfs_set_inode_size(leaf, inode_item, strlen(buf) * 2 + + btrfs_set_inode_size(leaf, inode_item, len * 2 + btrfs_inode_size(leaf, inode_item)); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(path); @@ -1487,13 +1496,13 @@ static struct btrfs_root * link_subvol(struct btrfs_root *root, ret = btrfs_add_root_ref(trans, tree_root, root_objectid, BTRFS_ROOT_BACKREF_KEY, root->root_key.objectid, - dirid, index, buf, strlen(buf)); + dirid, index, buf, len); BUG_ON(ret); /* now add the forward ref */ ret = btrfs_add_root_ref(trans, tree_root, root->root_key.objectid, BTRFS_ROOT_REF_KEY, root_objectid, - dirid, index, buf, strlen(buf)); + dirid, index, buf, len); ret = btrfs_commit_transaction(trans, root); BUG_ON(ret);