From patchwork Mon Nov 20 22:36:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ronnie Sahlberg X-Patchwork-Id: 839799 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-cifs-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3ygk965wBgz9sRn for ; Tue, 21 Nov 2017 09:36:42 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751154AbdKTWgl (ORCPT ); Mon, 20 Nov 2017 17:36:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47032 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751149AbdKTWgl (ORCPT ); Mon, 20 Nov 2017 17:36:41 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5EBCB61488; Mon, 20 Nov 2017 22:36:41 +0000 (UTC) Received: from test1190.test.redhat.com (vpn2-54-66.bne.redhat.com [10.64.54.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id 885505D6A6; Mon, 20 Nov 2017 22:36:40 +0000 (UTC) From: Ronnie Sahlberg To: linux-cifs Cc: Steve French Subject: [PATCH] cifs: fix NULL deref in SMB2_read Date: Tue, 21 Nov 2017 09:36:33 +1100 Message-Id: <20171120223633.16117-1-lsahlber@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 20 Nov 2017 22:36:41 +0000 (UTC) Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Signed-off-by: Ronnie Sahlberg Reviewed-by: Pavel Shilovsky --- fs/cifs/smb2pdu.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index f92b39bbb929..a555d2b39b30 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -2649,27 +2649,27 @@ SMB2_read(const unsigned int xid, struct cifs_io_parms *io_parms, cifs_small_buf_release(req); rsp = (struct smb2_read_rsp *)rsp_iov.iov_base; - shdr = get_sync_hdr(rsp); - if (shdr->Status == STATUS_END_OF_FILE) { + if (rc) { + if (rc != -ENODATA) { + cifs_stats_fail_inc(io_parms->tcon, SMB2_READ_HE); + cifs_dbg(VFS, "Send error in read = %d\n", rc); + } free_rsp_buf(resp_buftype, rsp_iov.iov_base); - return 0; + return rc == -ENODATA ? 0 : rc; } - if (rc) { - cifs_stats_fail_inc(io_parms->tcon, SMB2_READ_HE); - cifs_dbg(VFS, "Send error in read = %d\n", rc); - } else { - *nbytes = le32_to_cpu(rsp->DataLength); - if ((*nbytes > CIFS_MAX_MSGSIZE) || - (*nbytes > io_parms->length)) { - cifs_dbg(FYI, "bad length %d for count %d\n", - *nbytes, io_parms->length); - rc = -EIO; - *nbytes = 0; - } + *nbytes = le32_to_cpu(rsp->DataLength); + if ((*nbytes > CIFS_MAX_MSGSIZE) || + (*nbytes > io_parms->length)) { + cifs_dbg(FYI, "bad length %d for count %d\n", + *nbytes, io_parms->length); + rc = -EIO; + *nbytes = 0; } + shdr = get_sync_hdr(rsp); + if (*buf) { memcpy(*buf, (char *)shdr + rsp->DataOffset, *nbytes); free_rsp_buf(resp_buftype, rsp_iov.iov_base);