From patchwork Thu Oct 17 19:39:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 11197037 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 82A8D14DB for ; Thu, 17 Oct 2019 19:40:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6C38221A49 for ; Thu, 17 Oct 2019 19:40:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438990AbfJQTjp (ORCPT ); Thu, 17 Oct 2019 15:39:45 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:45046 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730180AbfJQTjp (ORCPT ); Thu, 17 Oct 2019 15:39:45 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1iLBcc-0006ez-Se; Thu, 17 Oct 2019 19:39:43 +0000 From: Al Viro To: linux-scsi@vger.kernel.org Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Al Viro Subject: [RFC PATCH 1/8] sg_ioctl(): fix copyout handling Date: Thu, 17 Oct 2019 20:39:18 +0100 Message-Id: <20191017193925.25539-1-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191017193659.GA18702@ZenIV.linux.org.uk> References: <20191017193659.GA18702@ZenIV.linux.org.uk> MIME-Version: 1.0 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Al Viro First of all, __put_user() can fail with access_ok() succeeding. And access_ok() + __copy_to_user() is spelled copy_to_user()... __put_user() *can* fail with access_ok() succeeding... Signed-off-by: Al Viro --- drivers/scsi/sg.c | 43 ++++++++++++++++--------------------------- 1 file changed, 16 insertions(+), 27 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index cce757506383..634460421ce4 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -963,26 +963,21 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) case SG_GET_LOW_DMA: return put_user((int) sdp->device->host->unchecked_isa_dma, ip); case SG_GET_SCSI_ID: - if (!access_ok(p, sizeof (sg_scsi_id_t))) - return -EFAULT; - else { - sg_scsi_id_t __user *sg_idp = p; + { + sg_scsi_id_t v; if (atomic_read(&sdp->detaching)) return -ENODEV; - __put_user((int) sdp->device->host->host_no, - &sg_idp->host_no); - __put_user((int) sdp->device->channel, - &sg_idp->channel); - __put_user((int) sdp->device->id, &sg_idp->scsi_id); - __put_user((int) sdp->device->lun, &sg_idp->lun); - __put_user((int) sdp->device->type, &sg_idp->scsi_type); - __put_user((short) sdp->device->host->cmd_per_lun, - &sg_idp->h_cmd_per_lun); - __put_user((short) sdp->device->queue_depth, - &sg_idp->d_queue_depth); - __put_user(0, &sg_idp->unused[0]); - __put_user(0, &sg_idp->unused[1]); + memset(&v, 0, sizeof(v)); + v.host_no = sdp->device->host->host_no; + v.channel = sdp->device->channel; + v.scsi_id = sdp->device->id; + v.lun = sdp->device->lun; + v.scsi_type = sdp->device->type; + v.h_cmd_per_lun = sdp->device->host->cmd_per_lun; + v.d_queue_depth = sdp->device->queue_depth; + if (copy_to_user(p, &v, sizeof(sg_scsi_id_t))) + return -EFAULT; return 0; } case SG_SET_FORCE_PACK_ID: @@ -992,20 +987,16 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) sfp->force_packid = val ? 1 : 0; return 0; case SG_GET_PACK_ID: - if (!access_ok(ip, sizeof (int))) - return -EFAULT; read_lock_irqsave(&sfp->rq_list_lock, iflags); list_for_each_entry(srp, &sfp->rq_list, entry) { if ((1 == srp->done) && (!srp->sg_io_owned)) { read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - __put_user(srp->header.pack_id, ip); - return 0; + return put_user(srp->header.pack_id, ip); } } read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - __put_user(-1, ip); - return 0; + return put_user(-1, ip); case SG_GET_NUM_WAITING: read_lock_irqsave(&sfp->rq_list_lock, iflags); val = 0; @@ -1073,9 +1064,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) val = (sdp->device ? 1 : 0); return put_user(val, ip); case SG_GET_REQUEST_TABLE: - if (!access_ok(p, SZ_SG_REQ_INFO * SG_MAX_QUEUE)) - return -EFAULT; - else { + { sg_req_info_t *rinfo; rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO, @@ -1085,7 +1074,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) read_lock_irqsave(&sfp->rq_list_lock, iflags); sg_fill_request_table(sfp, rinfo); read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - result = __copy_to_user(p, rinfo, + result = copy_to_user(p, rinfo, SZ_SG_REQ_INFO * SG_MAX_QUEUE); result = result ? -EFAULT : 0; kfree(rinfo);