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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 B95BEC43387 for ; Wed, 16 Jan 2019 16:29:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A68620675 for ; Wed, 16 Jan 2019 16:29:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726065AbfAPQ3C (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 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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); -- 2.19.1