Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751713AbdG0HLn (ORCPT ); Thu, 27 Jul 2017 03:11:43 -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 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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2073 Lines: 68 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: --- 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); -- 2.12.3