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 X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8383C18E7B for ; Mon, 10 May 2021 11:29:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 902B261139 for ; Mon, 10 May 2021 11:29:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235609AbhEJL03 (ORCPT ); Mon, 10 May 2021 07:26:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:46292 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234404AbhEJK4V (ORCPT ); Mon, 10 May 2021 06:56:21 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EDB3B616ED; Mon, 10 May 2021 10:45:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620643536; bh=sL8mAePdqq057TI8MfLqlL/X8aqFoffLn23YQzVzTiQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W94QhMnoBIskRxUTbzFflhxOtyus1XmMzmX7qVHodvUaZO2wj7Ok1AWfmttzeYExh FIOFG6qCokj2+U1sLQ5M/t4L0iSQp5oxYGVTysxb7R7Z/NMbI6BgjlP7Qk6QoXzHVj 863YemLX8NhbRxeMMR5rhQoFzikcmI+pHRTrz1fw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Paulo Alcantara (SUSE)" , David Disseldorp , Steve French Subject: [PATCH 5.11 053/342] cifs: fix regression when mounting shares with prefix paths Date: Mon, 10 May 2021 12:17:23 +0200 Message-Id: <20210510102011.877595827@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510102010.096403571@linuxfoundation.org> References: <20210510102010.096403571@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paulo Alcantara commit 5c1acf3fe05ce443edba5e2110c9e581765f66a8 upstream. The commit 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx") revealed an existing bug when mounting shares that contain a prefix path or DFS links. cifs_setup_volume_info() requires the @devname to contain the full path (UNC + prefix) to update the fs context with the new UNC and prepath values, however we were passing only the UNC path (old_ctx->UNC) in @device thus discarding any prefix paths. Instead of concatenating both old_ctx->{UNC,prepath} and pass it in @devname, just keep the dup'ed values of UNC and prepath in cifs_sb->ctx after calling smb3_fs_context_dup(), and fix smb3_parse_devname() to correctly parse and not leak the new UNC and prefix paths. Cc: # v5.11+ Fixes: 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx") Signed-off-by: Paulo Alcantara (SUSE) Acked-by: David Disseldorp Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/cifsfs.c | 8 +------- fs/cifs/connect.c | 24 ++++++++++++++++++------ fs/cifs/fs_context.c | 4 ++++ 3 files changed, 23 insertions(+), 13 deletions(-) --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -823,13 +823,7 @@ cifs_smb3_do_mount(struct file_system_ty goto out; } - /* cifs_setup_volume_info->smb3_parse_devname() redups UNC & prepath */ - kfree(cifs_sb->ctx->UNC); - cifs_sb->ctx->UNC = NULL; - kfree(cifs_sb->ctx->prepath); - cifs_sb->ctx->prepath = NULL; - - rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, old_ctx->UNC); + rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, NULL); if (rc) { root = ERR_PTR(rc); goto out; --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3150,17 +3150,29 @@ out: int cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname) { - int rc = 0; + int rc; - smb3_parse_devname(devname, ctx); + if (devname) { + cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname); + rc = smb3_parse_devname(devname, ctx); + if (rc) { + cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc); + return rc; + } + } if (mntopts) { char *ip; - cifs_dbg(FYI, "%s: mntopts=%s\n", __func__, mntopts); rc = smb3_parse_opt(mntopts, "ip", &ip); - if (!rc && !cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, - strlen(ip))) { + if (rc) { + cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc); + return rc; + } + + rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip)); + kfree(ip); + if (!rc) { cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__); return -EINVAL; } @@ -3180,7 +3192,7 @@ cifs_setup_volume_info(struct smb3_fs_co return -EINVAL; } - return rc; + return 0; } static int --- a/fs/cifs/fs_context.c +++ b/fs/cifs/fs_context.c @@ -473,6 +473,7 @@ smb3_parse_devname(const char *devname, /* move "pos" up to delimiter or NULL */ pos += len; + kfree(ctx->UNC); ctx->UNC = kstrndup(devname, pos - devname, GFP_KERNEL); if (!ctx->UNC) return -ENOMEM; @@ -483,6 +484,9 @@ smb3_parse_devname(const char *devname, if (*pos == '/' || *pos == '\\') pos++; + kfree(ctx->prepath); + ctx->prepath = NULL; + /* If pos is NULL then no prepath */ if (!*pos) return 0;