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 4D446C2D0D5 for ; Mon, 10 May 2021 12:02:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 42C6B613C2 for ; Mon, 10 May 2021 12:02:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245113AbhEJMDG (ORCPT ); Mon, 10 May 2021 08:03:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:46208 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236259AbhEJLHq (ORCPT ); Mon, 10 May 2021 07:07:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8176561954; Mon, 10 May 2021 10:59:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620644364; bh=EDuQGDSWvy3peju04Ji5/t2596MdhKU1EemSBf2j53E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=spIKQOASarFPp2ZHEUmd/nsxEDAO+GmJKeR/BifBqAfEXzzXPHkHoR5pNIvF6CiLm Akul7Z27DfY7/xyGnUiw54vortOC0IamQGy2S5PNYvb49u8XS6njNoC7ya5XOWO9ZU yAMXrJUpZ0t3OXI2qu4P84yYK4+aQgvtwpe5zzIc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Disseldorp , Ronnie Sahlberg , "Paulo Alcantara (SUSE)" , Steve French Subject: [PATCH 5.12 053/384] cifs: fix leak in cifs_smb3_do_mount() ctx Date: Mon, 10 May 2021 12:17:22 +0200 Message-Id: <20210510102016.625918286@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510102014.849075526@linuxfoundation.org> References: <20210510102014.849075526@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: David Disseldorp commit 315db9a05b7a56810728589baa930864107e4634 upstream. cifs_smb3_do_mount() calls smb3_fs_context_dup() and then cifs_setup_volume_info(). The latter's subsequent smb3_parse_devname() call overwrites the cifs_sb->ctx->UNC string already dup'ed by smb3_fs_context_dup(), resulting in a leak. E.g. unreferenced object 0xffff888002980420 (size 32): comm "mount", pid 160, jiffies 4294892541 (age 30.416s) hex dump (first 32 bytes): 5c 5c 31 39 32 2e 31 36 38 2e 31 37 34 2e 31 30 \\192.168.174.10 34 5c 72 61 70 69 64 6f 2d 73 68 61 72 65 00 00 4\rapido-share.. backtrace: [<00000000069e12f6>] kstrdup+0x28/0x50 [<00000000b61f4032>] smb3_fs_context_dup+0x127/0x1d0 [cifs] [<00000000c6e3e3bf>] cifs_smb3_do_mount+0x77/0x660 [cifs] [<0000000063467a6b>] smb3_get_tree+0xdf/0x220 [cifs] [<00000000716f731e>] vfs_get_tree+0x1b/0x90 [<00000000491d3892>] path_mount+0x62a/0x910 [<0000000046b2e774>] do_mount+0x50/0x70 [<00000000ca7b64dd>] __x64_sys_mount+0x81/0xd0 [<00000000b5122496>] do_syscall_64+0x33/0x40 [<000000002dd397af>] entry_SYSCALL_64_after_hwframe+0x44/0xae This change is a bandaid until the cifs_setup_volume_info() TODO and error handling issues are resolved. Signed-off-by: David Disseldorp Acked-by: Ronnie Sahlberg Reviewed-by: Paulo Alcantara (SUSE) CC: # v5.11+ Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/cifsfs.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -834,6 +834,12 @@ 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); if (rc) { root = ERR_PTR(rc);