From patchwork Wed Jan 16 16:28:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 10766403 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 32E0313A4 for ; Wed, 16 Jan 2019 16:29:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 195D92AD44 for ; Wed, 16 Jan 2019 16:29:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0BDBE2E3FE; Wed, 16 Jan 2019 16:29:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8C7F72AD44 for ; Wed, 16 Jan 2019 16:29:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725648AbfAPQ3C (ORCPT ); Wed, 16 Jan 2019 11:29:02 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:47073 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725385AbfAPQ3C (ORCPT ); Wed, 16 Jan 2019 11:29:02 -0500 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1gjo3n-0003IV-VF; Wed, 16 Jan 2019 16:29:00 +0000 From: Colin King To: Steve French , linux-cifs@vger.kernel.org, samba-technical@lists.samba.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][V2] cifs: fix memory leak of an allocated cifs_ntsd structure Date: Wed, 16 Jan 2019 16:28:59 +0000 Message-Id: <20190116162859.8028-1-colin.king@canonical.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Colin Ian King The call to SMB2_queary_acl can allocate memory to pntsd and also return a failure via a call to SMB2_query_acl (and then query_info). This occurs when query_info allocates the structure and then in query_info the call to smb2_validate_and_copy_iov fails. Currently the failure just returns without kfree'ing pntsd hence causing a memory leak. Currently, *data is allocated if it's not already pointing to a buffer, so it needs to be kfree'd only if was allocated in query_info, so the fix adds an allocated flag to track this. Also set *dlen to zero on an error just to be safe since *data is kfree'd. Also set errno to -ENOMEM if the allocation of *data fails. Signed-off-by: Colin Ian King Reviewed-by: Dan Carpener --- fs/cifs/smb2pdu.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 50811a7dc0e0..0af87bd0dc49 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -2816,6 +2816,7 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon, int resp_buftype = CIFS_NO_BUFFER; struct cifs_ses *ses = tcon->ses; int flags = 0; + bool allocated = false; cifs_dbg(FYI, "Query Info\n"); @@ -2855,14 +2856,21 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon, "Error %d allocating memory for acl\n", rc); *dlen = 0; + rc = -ENOMEM; goto qinf_exit; } + allocated = true; } } rc = smb2_validate_and_copy_iov(le16_to_cpu(rsp->OutputBufferOffset), le32_to_cpu(rsp->OutputBufferLength), &rsp_iov, min_len, *data); + if (rc && allocated) { + kfree(*data); + *data = NULL; + *dlen = 0; + } qinf_exit: SMB2_query_info_free(&rqst);