From patchwork Wed Apr 25 18:30:04 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Long Li X-Patchwork-Id: 10364165 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id AC81D6032C for ; Wed, 25 Apr 2018 18:31:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 99712287CB for ; Wed, 25 Apr 2018 18:31:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8D746287EA; Wed, 25 Apr 2018 18:31:53 +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=unavailable 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 141C327DA4 for ; Wed, 25 Apr 2018 18:31:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755062AbeDYSbi (ORCPT ); Wed, 25 Apr 2018 14:31:38 -0400 Received: from a2nlsmtp01-04.prod.iad2.secureserver.net ([198.71.225.38]:54044 "EHLO a2nlsmtp01-04.prod.iad2.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754974AbeDYSbe (ORCPT ); Wed, 25 Apr 2018 14:31:34 -0400 Received: from linuxonhyperv2.linuxonhyperv.com ([107.180.71.197]) by : HOSTING RELAY : with SMTP id BPBEfOZpaGqYmBPBEfxqrI; Wed, 25 Apr 2018 11:30:32 -0700 x-originating-ip: 107.180.71.197 Received: from longli by linuxonhyperv2.linuxonhyperv.com with local (Exim 4.89_1) (envelope-from ) id 1fBPBE-0002RT-M3; Wed, 25 Apr 2018 11:30:12 -0700 From: Long Li To: Steve French , linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org Cc: Long Li Subject: [PATCH v5] cifs: Allocate validate negotiation request through kmalloc Date: Wed, 25 Apr 2018 11:30:04 -0700 Message-Id: <20180425183005.9347-1-longli@linuxonhyperv.com> X-Mailer: git-send-email 2.15.1 Reply-To: longli@microsoft.com X-CMAE-Envelope: MS4wfH6r45S6KjTSZUrWAtpM02/by3TJzKxEsqrexRuX5au4FVonuX5JX6AcbAu9J/Q2TYqQf+rmcvKnSpK1Ih0wM14M7FZipjCUGT3Sj+/j70JMIoDxgBBF dwXvg60og191R2aAQUJyJr6ksRxZyl8xDD7VgCYUSu35v5YzfHhx8D4B5IWDbIapIzKZpQpYFkxDk7COQqw+r2YowEP5OjVMqACH0yGaXz153XIfxIpN263p Cg8gAR+wLepTFk9pEGWJ5SQmwBlcqQ/Px4QBIjABMxMuzCCbpl+yrP0wU5cz/MgRDdjSbJk/L0W5Q3A/1zo/1rrq9AwVRLJ8PvCQsxVpjX6LcDESYX1i3fJk 1V3n55L+oWMRXIHxU4UcU42CiY5YO0zJwBNnxRebiXSEpabLN6Xc2R0I+Ex+hBJIfxbuHgu8 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: Long Li The data buffer allocated on the stack can't be DMA'ed, ib_dma_map_page will return an invalid DMA address for a buffer on stack. Even worse, this incorrect address can't be detected by ib_dma_mapping_error. Sending data from this address to hardware will not fail, but the remote peer will get junk data. Fix this by allocating the request on the heap in smb3_validate_negotiate. Changes in v2: Removed duplicated code on freeing buffers on function exit. (Thanks to Parav Pandit ) Fixed typo in the patch title. Changes in v3: Added "Fixes" to the patch. Changed several sizeof() to use *pointer in place of struct. Changes in v4: Added detailed comments on the failure through RDMA. Allocate request buffer using GPF_NOFS. Fixed possible memory leak. Changes in v5: Removed variable ret for checking return value. Changed to use pneg_inbuf->Dialects[0] to calculate unused space in pneg_inbuf. Fixes: ff1c038addc4 ("Check SMB3 dialects against downgrade attacks") Signed-off-by: Long Li Reviewed-By: Tom Talpey --- fs/cifs/smb2pdu.c | 68 +++++++++++++++++++++++++++++++------------------------ 1 file changed, 38 insertions(+), 30 deletions(-) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 0f044c4..66f1a7b 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -729,8 +729,8 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses) int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon) { - int rc = 0; - struct validate_negotiate_info_req vneg_inbuf; + int rc; + struct validate_negotiate_info_req *pneg_inbuf; struct validate_negotiate_info_rsp *pneg_rsp = NULL; u32 rsplen; u32 inbuflen; /* max of 4 dialects */ @@ -764,63 +764,69 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon) if (tcon->ses->session_flags & SMB2_SESSION_FLAG_IS_NULL) cifs_dbg(VFS, "Unexpected null user (anonymous) auth flag sent by server\n"); - vneg_inbuf.Capabilities = + pneg_inbuf = kmalloc(sizeof(*pneg_inbuf), GFP_NOFS); + if (!pneg_inbuf) + return -ENOMEM; + + pneg_inbuf->Capabilities = cpu_to_le32(tcon->ses->server->vals->req_capabilities); - memcpy(vneg_inbuf.Guid, tcon->ses->server->client_guid, + memcpy(pneg_inbuf->Guid, tcon->ses->server->client_guid, SMB2_CLIENT_GUID_SIZE); if (tcon->ses->sign) - vneg_inbuf.SecurityMode = + pneg_inbuf->SecurityMode = cpu_to_le16(SMB2_NEGOTIATE_SIGNING_REQUIRED); else if (global_secflags & CIFSSEC_MAY_SIGN) - vneg_inbuf.SecurityMode = + pneg_inbuf->SecurityMode = cpu_to_le16(SMB2_NEGOTIATE_SIGNING_ENABLED); else - vneg_inbuf.SecurityMode = 0; + pneg_inbuf->SecurityMode = 0; if (strcmp(tcon->ses->server->vals->version_string, SMB3ANY_VERSION_STRING) == 0) { - vneg_inbuf.Dialects[0] = cpu_to_le16(SMB30_PROT_ID); - vneg_inbuf.Dialects[1] = cpu_to_le16(SMB302_PROT_ID); - vneg_inbuf.DialectCount = cpu_to_le16(2); + pneg_inbuf->Dialects[0] = cpu_to_le16(SMB30_PROT_ID); + pneg_inbuf->Dialects[1] = cpu_to_le16(SMB302_PROT_ID); + pneg_inbuf->DialectCount = cpu_to_le16(2); /* structure is big enough for 3 dialects, sending only 2 */ - inbuflen = sizeof(struct validate_negotiate_info_req) - 2; + inbuflen = sizeof(*pneg_inbuf) - + sizeof(pneg_inbuf->Dialects[0]); } else if (strcmp(tcon->ses->server->vals->version_string, SMBDEFAULT_VERSION_STRING) == 0) { - vneg_inbuf.Dialects[0] = cpu_to_le16(SMB21_PROT_ID); - vneg_inbuf.Dialects[1] = cpu_to_le16(SMB30_PROT_ID); - vneg_inbuf.Dialects[2] = cpu_to_le16(SMB302_PROT_ID); - vneg_inbuf.DialectCount = cpu_to_le16(3); + pneg_inbuf->Dialects[0] = cpu_to_le16(SMB21_PROT_ID); + pneg_inbuf->Dialects[1] = cpu_to_le16(SMB30_PROT_ID); + pneg_inbuf->Dialects[2] = cpu_to_le16(SMB302_PROT_ID); + pneg_inbuf->DialectCount = cpu_to_le16(3); /* structure is big enough for 3 dialects */ - inbuflen = sizeof(struct validate_negotiate_info_req); + inbuflen = sizeof(*pneg_inbuf); } else { /* otherwise specific dialect was requested */ - vneg_inbuf.Dialects[0] = + pneg_inbuf->Dialects[0] = cpu_to_le16(tcon->ses->server->vals->protocol_id); - vneg_inbuf.DialectCount = cpu_to_le16(1); + pneg_inbuf->DialectCount = cpu_to_le16(1); /* structure is big enough for 3 dialects, sending only 1 */ - inbuflen = sizeof(struct validate_negotiate_info_req) - 4; + inbuflen = sizeof(*pneg_inbuf) - + sizeof(pneg_inbuf->Dialects[0]) * 2; } rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID, FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */, - (char *)&vneg_inbuf, sizeof(struct validate_negotiate_info_req), - (char **)&pneg_rsp, &rsplen); + (char *)pneg_inbuf, inbuflen, (char **)&pneg_rsp, &rsplen); if (rc != 0) { cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc); - return -EIO; + rc = -EIO; + goto out_free_inbuf; } - if (rsplen != sizeof(struct validate_negotiate_info_rsp)) { + rc = -EIO; + if (rsplen != sizeof(*pneg_rsp)) { cifs_dbg(VFS, "invalid protocol negotiate response size: %d\n", rsplen); /* relax check since Mac returns max bufsize allowed on ioctl */ - if ((rsplen > CIFSMaxBufSize) - || (rsplen < sizeof(struct validate_negotiate_info_rsp))) - goto err_rsp_free; + if (rsplen > CIFSMaxBufSize || rsplen < sizeof(*pneg_rsp)) + goto out_free_rsp; } /* check validate negotiate info response matches what we got earlier */ @@ -837,15 +843,17 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon) goto vneg_out; /* validate negotiate successful */ + rc = 0; cifs_dbg(FYI, "validate negotiate info successful\n"); - kfree(pneg_rsp); - return 0; + goto out_free_rsp; vneg_out: cifs_dbg(VFS, "protocol revalidation - security settings mismatch\n"); -err_rsp_free: +out_free_rsp: kfree(pneg_rsp); - return -EIO; +out_free_inbuf: + kfree(pneg_inbuf); + return rc; } enum securityEnum