From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-cys01nam02on0130.outbound.protection.outlook.com ([104.47.37.130]:16451 "EHLO NAM02-CY1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S966090AbeCHFFK (ORCPT ); Thu, 8 Mar 2018 00:05:10 -0500 From: Sasha Levin To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" CC: Johannes Thumshirn , Hannes Reinecke , "Martin K . Petersen" , Sasha Levin Subject: [PATCH AUTOSEL for 4.4 005/101] scsi: sg: check for valid direction before starting the request Date: Thu, 8 Mar 2018 05:01:09 +0000 Message-ID: <20180308050023.8548-5-alexander.levin@microsoft.com> References: <20180308050023.8548-1-alexander.levin@microsoft.com> In-Reply-To: <20180308050023.8548-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org List-ID: From: Johannes Thumshirn [ Upstream commit 28676d869bbb5257b5f14c0c95ad3af3a7019dd5 ] Check for a valid direction before starting the request, otherwise we risk running into an assertion in the scsi midlayer checking for valid requests. [mkp: fixed typo] Signed-off-by: Johannes Thumshirn Link: http://www.spinics.net/lists/linux-scsi/msg104400.html Reported-by: Dmitry Vyukov Signed-off-by: Hannes Reinecke Tested-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/sg.c | 46 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 34 insertions(+), 12 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 0f0ff75755e0..27f92f4ea6bc 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -674,18 +674,14 @@ sg_write(struct file *filp, const char __user *buf, s= ize_t count, loff_t * ppos) * is a non-zero input_size, so emit a warning. */ if (hp->dxfer_direction =3D=3D SG_DXFER_TO_FROM_DEV) { - static char cmd[TASK_COMM_LEN]; - if (strcmp(current->comm, cmd)) { - printk_ratelimited(KERN_WARNING - "sg_write: data in/out %d/%d bytes " - "for SCSI command 0x%x-- guessing " - "data in;\n program %s not setting " - "count and/or reply_len properly\n", - old_hdr.reply_len - (int)SZ_SG_HEADER, - input_size, (unsigned int) cmnd[0], - current->comm); - strcpy(cmd, current->comm); - } + printk_ratelimited(KERN_WARNING + "sg_write: data in/out %d/%d bytes " + "for SCSI command 0x%x-- guessing " + "data in;\n program %s not setting " + "count and/or reply_len properly\n", + old_hdr.reply_len - (int)SZ_SG_HEADER, + input_size, (unsigned int) cmnd[0], + current->comm); } k =3D sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking); return (k < 0) ? k : count; @@ -764,6 +760,29 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char= __user *buf, return count; } =20 +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_TO_DEV: + case SG_DXFER_FROM_DEV: + case SG_DXFER_TO_FROM_DEV: + if (!hp->dxferp || hp->dxfer_len =3D=3D 0) + return false; + return true; + case SG_DXFER_UNKNOWN: + if ((!hp->dxferp && hp->dxfer_len) || + (hp->dxferp && hp->dxfer_len =3D=3D 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) @@ -784,6 +803,9 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp, "sg_common_write: scsi opcode=3D0x%02x, cmd_size=3D%d\n", (int) cmnd[0], (int) hp->cmd_len)); =20 + if (!sg_is_valid_dxfer(hp)) + return -EINVAL; + k =3D sg_start_req(srp, cmnd); if (k) { SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp, --=20 2.14.1