From patchwork Fri Jul 6 21:38:54 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 10512569 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 203876024A for ; Fri, 6 Jul 2018 21:39:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1111228587 for ; Fri, 6 Jul 2018 21:39:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 04DC3287E9; Fri, 6 Jul 2018 21:39:11 +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=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID 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 87F5828587 for ; Fri, 6 Jul 2018 21:39:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754324AbeGFVi6 (ORCPT ); Fri, 6 Jul 2018 17:38:58 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:50850 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753729AbeGFVi4 (ORCPT ); Fri, 6 Jul 2018 17:38:56 -0400 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 3F9098EE212; Fri, 6 Jul 2018 14:38:56 -0700 (PDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id j516mH0b6EF4; Fri, 6 Jul 2018 14:38:56 -0700 (PDT) Received: from [153.66.254.194] (unknown [50.35.68.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id D7C668EE02B; Fri, 6 Jul 2018 14:38:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1530913136; bh=O3CftAatTORKzSa2HdrKZ5QHkzJ7iMaa9K2Vnhdijrc=; h=Subject:From:To:Cc:Date:From; b=lByR5WTWZwL4Qel9pCek+M6xi4c+lBSu8suLzuYtx72rWURpDkgqOVr9mw8oYuBuw eexZKOIGnhqJxk5Q/JUJMaZygSKzwstxo4waWMA19gIocA/eqru8jISOXZZQ/GDqAe UAPIixGPGPOymS3pXuWqGfZYWLQ4xztDLTTZmk28= Message-ID: <1530913134.3135.2.camel@HansenPartnership.com> Subject: [GIT PULL] SCSI fixes for 4.18-rc3 From: James Bottomley To: Andrew Morton , Linus Torvalds Cc: linux-scsi , linux-kernel Date: Fri, 06 Jul 2018 14:38:54 -0700 X-Mailer: Evolution 3.22.6 Mime-Version: 1.0 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 This is two minor bug fixes (aacraid, target) and a fix for a potential exploit in the way sg handles teardown. The patch is available here: git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes The short changelog is: David Disseldorp (1): scsi: target: Fix truncated PR-in ReadKeys response Jann Horn (1): scsi: sg: mitigate read/write abuse Raghava Aditya Renukunta (1): scsi: aacraid: Fix PD performance regression over incorrect qd being set And the diffstat: drivers/scsi/aacraid/aachba.c | 15 +++++++-------- drivers/scsi/sg.c | 42 +++++++++++++++++++++++++++++++++++++++-- drivers/target/target_core_pr.c | 15 ++++++++++----- 3 files changed, 57 insertions(+), 15 deletions(-) With full diff below. James diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c index a9831bd37a73..a57f3a7d4748 100644 --- a/drivers/scsi/aacraid/aachba.c +++ b/drivers/scsi/aacraid/aachba.c @@ -1974,7 +1974,6 @@ static void aac_set_safw_attr_all_targets(struct aac_dev *dev) u32 lun_count, nexus; u32 i, bus, target; u8 expose_flag, attribs; - u8 devtype; lun_count = aac_get_safw_phys_lun_count(dev); @@ -1992,23 +1991,23 @@ static void aac_set_safw_attr_all_targets(struct aac_dev *dev) continue; if (expose_flag != 0) { - devtype = AAC_DEVTYPE_RAID_MEMBER; - goto update_devtype; + dev->hba_map[bus][target].devtype = + AAC_DEVTYPE_RAID_MEMBER; + continue; } if (nexus != 0 && (attribs & 8)) { - devtype = AAC_DEVTYPE_NATIVE_RAW; + dev->hba_map[bus][target].devtype = + AAC_DEVTYPE_NATIVE_RAW; dev->hba_map[bus][target].rmw_nexus = nexus; } else - devtype = AAC_DEVTYPE_ARC_RAW; + dev->hba_map[bus][target].devtype = + AAC_DEVTYPE_ARC_RAW; dev->hba_map[bus][target].scan_counter = dev->scan_counter; aac_set_safw_target_qd(dev, bus, target); - -update_devtype: - dev->hba_map[bus][target].devtype = devtype; } } diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 53ae52dbff84..cd2fdac000c9 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -51,6 +51,7 @@ static int sg_version_num = 30536; /* 2 digits for each component */ #include #include #include +#include /* for sg_check_file_access() */ #include "scsi.h" #include @@ -209,6 +210,33 @@ static void sg_device_destroy(struct kref *kref); sdev_prefix_printk(prefix, (sdp)->device, \ (sdp)->disk->disk_name, fmt, ##a) +/* + * The SCSI interfaces that use read() and write() as an asynchronous variant of + * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways + * to trigger read() and write() calls from various contexts with elevated + * privileges. This can lead to kernel memory corruption (e.g. if these + * interfaces are called through splice()) and privilege escalation inside + * userspace (e.g. if a process with access to such a device passes a file + * descriptor to a SUID binary as stdin/stdout/stderr). + * + * This function provides protection for the legacy API by restricting the + * calling context. + */ +static int sg_check_file_access(struct file *filp, const char *caller) +{ + if (filp->f_cred != current_real_cred()) { + pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n", + caller, task_tgid_vnr(current), current->comm); + return -EPERM; + } + if (uaccess_kernel()) { + pr_err_once("%s: process %d (%s) called from kernel context, this is not allowed.\n", + caller, task_tgid_vnr(current), current->comm); + return -EACCES; + } + return 0; +} + static int sg_allow_access(struct file *filp, unsigned char *cmd) { struct sg_fd *sfp = filp->private_data; @@ -393,6 +421,14 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) struct sg_header *old_hdr = NULL; int retval = 0; + /* + * This could cause a response to be stranded. Close the associated + * file descriptor to free up any resources being held. + */ + retval = sg_check_file_access(filp, __func__); + if (retval) + return retval; + if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) return -ENXIO; SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, @@ -580,9 +616,11 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) struct sg_header old_hdr; sg_io_hdr_t *hp; unsigned char cmnd[SG_MAX_CDB_SIZE]; + int retval; - if (unlikely(uaccess_kernel())) - return -EINVAL; + retval = sg_check_file_access(filp, __func__); + if (retval) + return retval; if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) return -ENXIO; diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c index 01ac306131c1..10db5656fd5d 100644 --- a/drivers/target/target_core_pr.c +++ b/drivers/target/target_core_pr.c @@ -3727,11 +3727,16 @@ core_scsi3_pri_read_keys(struct se_cmd *cmd) * Check for overflow of 8byte PRI READ_KEYS payload and * next reservation key list descriptor. */ - if ((add_len + 8) > (cmd->data_length - 8)) - break; - - put_unaligned_be64(pr_reg->pr_res_key, &buf[off]); - off += 8; + if (off + 8 <= cmd->data_length) { + put_unaligned_be64(pr_reg->pr_res_key, &buf[off]); + off += 8; + } + /* + * SPC5r17: 6.16.2 READ KEYS service action + * The ADDITIONAL LENGTH field indicates the number of bytes in + * the Reservation key list. The contents of the ADDITIONAL + * LENGTH field are not altered based on the allocation length + */ add_len += 8; } spin_unlock(&dev->t10_pr.registration_lock);