From patchwork Mon Aug 27 19:45:15 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Christie X-Patchwork-Id: 10577537 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AB996139B for ; Mon, 27 Aug 2018 19:45:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9FE5029FDD for ; Mon, 27 Aug 2018 19:45:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 93BDF2A0F5; Mon, 27 Aug 2018 19:45:22 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 CF15429FDD for ; Mon, 27 Aug 2018 19:45:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727233AbeH0XdU (ORCPT ); Mon, 27 Aug 2018 19:33:20 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:59250 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727023AbeH0XdU (ORCPT ); Mon, 27 Aug 2018 19:33:20 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D189A88846; Mon, 27 Aug 2018 19:45:18 +0000 (UTC) Received: from rh2.redhat.com (ovpn-123-78.rdu2.redhat.com [10.10.123.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id 57B992027EA0; Mon, 27 Aug 2018 19:45:18 +0000 (UTC) From: Mike Christie To: willy@infradead.org, martin.petersen@oracle.com, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, nab@linux-iscsi.org Cc: Vincent Pelletier , Mike Christie Subject: [PATCH 1/2] iscsi target: Set conn->sess to NULL when iscsi_login_set_conn_values fails Date: Mon, 27 Aug 2018 14:45:15 -0500 Message-Id: <1535399116-15138-2-git-send-email-mchristi@redhat.com> In-Reply-To: <1535399116-15138-1-git-send-email-mchristi@redhat.com> References: <1535399116-15138-1-git-send-email-mchristi@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 27 Aug 2018 19:45:18 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 27 Aug 2018 19:45:18 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mchristi@redhat.com' RCPT:'' 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 From: Vincent Pelletier Fixes a use-after-free reported by KASAN when later iscsi_target_login_sess_out gets called and it tries to access conn->sess->se_sess: Disabling lock debugging due to kernel taint iSCSI Login timeout on Network Portal [::]:3260 iSCSI Login negotiation failed. Reviewed-by: Matthew Wilcox ================================================================== BUG: KASAN: use-after-free in iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod] Read of size 8 at addr ffff880109d070c8 by task iscsi_np/980 CPU: 1 PID: 980 Comm: iscsi_np Tainted: G O 4.17.8kasan.sess.connops+ #4 Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 05/19/2014 Call Trace: dump_stack+0x71/0xac print_address_description+0x65/0x22e ? iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod] kasan_report.cold.6+0x241/0x2fd iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod] iscsi_target_login_thread+0x1086/0x1710 [iscsi_target_mod] ? __sched_text_start+0x8/0x8 ? iscsi_target_login_sess_out+0x250/0x250 [iscsi_target_mod] ? __kthread_parkme+0xcc/0x100 ? parse_args.cold.14+0xd3/0xd3 ? iscsi_target_login_sess_out+0x250/0x250 [iscsi_target_mod] kthread+0x1a0/0x1c0 ? kthread_bind+0x30/0x30 ret_from_fork+0x35/0x40 Allocated by task 980: kasan_kmalloc+0xbf/0xe0 kmem_cache_alloc_trace+0x112/0x210 iscsi_target_login_thread+0x816/0x1710 [iscsi_target_mod] kthread+0x1a0/0x1c0 ret_from_fork+0x35/0x40 Freed by task 980: __kasan_slab_free+0x125/0x170 kfree+0x90/0x1d0 iscsi_target_login_thread+0x1577/0x1710 [iscsi_target_mod] kthread+0x1a0/0x1c0 ret_from_fork+0x35/0x40 The buggy address belongs to the object at ffff880109d06f00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 456 bytes inside of 512-byte region [ffff880109d06f00, ffff880109d07100) The buggy address belongs to the page: page:ffffea0004274180 count:1 mapcount:0 mapping:0000000000000000 index:0x0 compound_mapcount: 0 flags: 0x17fffc000008100(slab|head) raw: 017fffc000008100 0000000000000000 0000000000000000 00000001000c000c raw: dead000000000100 dead000000000200 ffff88011b002e00 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff880109d06f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880109d07000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff880109d07080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880109d07100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff880109d07180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Signed-off-by: Vincent Pelletier [rebased against idr/ida changes and to handle ret review comments from Matthew] Signed-off-by: Mike Christie Cc: Matthew Wilcox --- v2: - Rebase against Linus's tree with idr/ida changes. - Always return -ENOMEM on failure because caller does not care and to simplify the code. drivers/target/iscsi/iscsi_target_login.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c index 9e74f8b..f58b9c1 100644 --- a/drivers/target/iscsi/iscsi_target_login.c +++ b/drivers/target/iscsi/iscsi_target_login.c @@ -310,11 +310,9 @@ static int iscsi_login_zero_tsih_s1( return -ENOMEM; } - ret = iscsi_login_set_conn_values(sess, conn, pdu->cid); - if (unlikely(ret)) { - kfree(sess); - return ret; - } + if (iscsi_login_set_conn_values(sess, conn, pdu->cid)) + goto free_sess; + sess->init_task_tag = pdu->itt; memcpy(&sess->isid, pdu->isid, 6); sess->exp_cmd_sn = be32_to_cpu(pdu->cmdsn);