From patchwork Thu Jul 27 07:11:26 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Thumshirn X-Patchwork-Id: 9866367 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 87B4E6038F for ; Thu, 27 Jul 2017 07:11:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7A6A0287ED for ; Thu, 27 Jul 2017 07:11:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6D698287F0; Thu, 27 Jul 2017 07:11:57 +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=-6.9 required=2.0 tests=BAYES_00,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 EDB01287ED for ; Thu, 27 Jul 2017 07:11:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751597AbdG0HLm (ORCPT ); Thu, 27 Jul 2017 03:11:42 -0400 Received: from mx2.suse.de ([195.135.220.15]:42172 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750989AbdG0HLl (ORCPT ); Thu, 27 Jul 2017 03:11:41 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E1321ABBC; Thu, 27 Jul 2017 07:11:39 +0000 (UTC) From: Johannes Thumshirn To: "Martin K . Petersen" Cc: Jason L Tibbitts III , Doug Gilbert , Linux Kernel Mailinglist , Linux SCSI Mailinglist , Hannes Reinecke , Johannes Thumshirn , stable@vger.kernel.org Subject: [PATCH] scsi: sg: only check for dxfer_len greater than 256M Date: Thu, 27 Jul 2017 09:11:26 +0200 Message-Id: <20170727071126.4717-1-jthumshirn@suse.de> X-Mailer: git-send-email 2.12.3 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Don't make any assumptions on the sg_io_hdr_t::dxfer_direction or the sg_io_hdr_t::dxferp in order to determine if it is a valid request. The only way we can check for bad requests is by checking if the length exceeds 256M. Signed-off-by: Johannes Thumshirn Fixes: 28676d869bbb (scsi: sg: check for valid direction before starting the request) Reported-by: Jason L Tibbitts III Tested-by: Jason L Tibbitts III Suggested-by: Doug Gilbert Cc: Doug Gilbert Cc: Reviewed-by: Hannes Reinecke --- drivers/scsi/sg.c | 31 +------------------------------ 1 file changed, 1 insertion(+), 30 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 4fe606b000b4..d7ff71e0c85c 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -751,35 +751,6 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, return count; } -static bool sg_is_valid_dxfer(sg_io_hdr_t *hp) -{ - switch (hp->dxfer_direction) { - case SG_DXFER_NONE: - if (hp->dxferp || hp->dxfer_len > 0) - return false; - return true; - case SG_DXFER_FROM_DEV: - /* - * for SG_DXFER_FROM_DEV we always set dxfer_len to > 0. dxferp - * can either be NULL or != NULL so there's no point in checking - * it either. So just return true. - */ - return true; - case SG_DXFER_TO_DEV: - case SG_DXFER_TO_FROM_DEV: - if (!hp->dxferp || hp->dxfer_len == 0) - return false; - return true; - case SG_DXFER_UNKNOWN: - if ((!hp->dxferp && hp->dxfer_len) || - (hp->dxferp && hp->dxfer_len == 0)) - return false; - return true; - default: - return false; - } -} - static int sg_common_write(Sg_fd * sfp, Sg_request * srp, unsigned char *cmnd, int timeout, int blocking) @@ -800,7 +771,7 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp, "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) cmnd[0], (int) hp->cmd_len)); - if (!sg_is_valid_dxfer(hp)) + if (hp->dxfer_len >= SZ_256M) return -EINVAL; k = sg_start_req(srp, cmnd);