From patchwork Thu Dec 26 20:31:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriel Krisman Bertazi X-Patchwork-Id: 11310717 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 D1BFF921 for ; Thu, 26 Dec 2019 20:31:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B91AB2080D for ; Thu, 26 Dec 2019 20:31:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726831AbfLZUbz (ORCPT ); Thu, 26 Dec 2019 15:31:55 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:37184 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726653AbfLZUbz (ORCPT ); Thu, 26 Dec 2019 15:31:55 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id 6BF1A27FDC0 From: Gabriel Krisman Bertazi To: lduncan@suse.com Cc: cleech@redhat.com, martin.petersen@oracle.com, open-iscsi@googlegroups.com, linux-scsi@vger.kernel.org, kernel@collabora.com Subject: [PATCH RESEND] iscsi: Don't destroy session if there are outstanding connections Date: Thu, 26 Dec 2019 15:31:48 -0500 Message-Id: <20191226203148.2172200-1-krisman@collabora.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Nick Black Hi, I thought this was already committed for some reason, until it bit me again today. Any opposition to this one? >8 A faulty userspace that calls destroy_session() before destroying the connections can trigger the failure. This patch prevents the issue by refusing to destroy the session if there are outstanding connections. ------------[ cut here ]------------ kernel BUG at mm/slub.c:306! invalid opcode: 0000 [#1] SMP PTI CPU: 1 PID: 1224 Comm: iscsid Not tainted 5.4.0-rc2.iscsi+ #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:__slab_free+0x181/0x350 [...] [ 1209.686056] RSP: 0018:ffffa93d4074fae0 EFLAGS: 00010246 [ 1209.686694] RAX: ffff934efa5ad800 RBX: 000000008010000a RCX: ffff934efa5ad800 [ 1209.687651] RDX: ffff934efa5ad800 RSI: ffffeb4041e96b00 RDI: ffff934efd402c40 [ 1209.688582] RBP: ffffa93d4074fb80 R08: 0000000000000001 R09: ffffffffbb5dfa26 [ 1209.689425] R10: ffff934efa5ad800 R11: 0000000000000001 R12: ffffeb4041e96b00 [ 1209.690285] R13: ffff934efa5ad800 R14: ffff934efd402c40 R15: 0000000000000000 [ 1209.691213] FS: 00007f7945dfb540(0000) GS:ffff934efda80000(0000) knlGS:0000000000000000 [ 1209.692316] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1209.693013] CR2: 000055877fd3da80 CR3: 0000000077384000 CR4: 00000000000006e0 [ 1209.693897] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1209.694773] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1209.695631] Call Trace: [ 1209.695957] ? __wake_up_common_lock+0x8a/0xc0 [ 1209.696712] iscsi_pool_free+0x26/0x40 [ 1209.697263] iscsi_session_teardown+0x2f/0xf0 [ 1209.698117] iscsi_sw_tcp_session_destroy+0x45/0x60 [ 1209.698831] iscsi_if_rx+0xd88/0x14e0 [ 1209.699370] netlink_unicast+0x16f/0x200 [ 1209.699932] netlink_sendmsg+0x21a/0x3e0 [ 1209.700446] sock_sendmsg+0x4f/0x60 [ 1209.700902] ___sys_sendmsg+0x2ae/0x320 [ 1209.701451] ? cp_new_stat+0x150/0x180 [ 1209.701922] __sys_sendmsg+0x59/0xa0 [ 1209.702357] do_syscall_64+0x52/0x160 [ 1209.702812] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1209.703419] RIP: 0033:0x7f7946433914 [...] [ 1209.706084] RSP: 002b:00007fffb99f2378 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 1209.706994] RAX: ffffffffffffffda RBX: 000055bc869eac20 RCX: 00007f7946433914 [ 1209.708082] RDX: 0000000000000000 RSI: 00007fffb99f2390 RDI: 0000000000000005 [ 1209.709120] RBP: 00007fffb99f2390 R08: 000055bc84fe9320 R09: 00007fffb99f1f07 [ 1209.710110] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000038 [ 1209.711085] R13: 000055bc8502306e R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace a2d933ede7f730d8 ]--- Co-developed-by: Salman Qazi Signed-off-by: Salman Qazi Co-developed-by: Junho Ryu Signed-off-by: Junho Ryu Co-developed-by: Khazhismel Kumykov Signed-off-by: Khazhismel Kumykov Signed-off-by: Nick Black Co-developed-by: Gabriel Krisman Bertazi Signed-off-by: Gabriel Krisman Bertazi Reviewed-by: Lee Duncan --- drivers/scsi/iscsi_tcp.c | 4 ++++ drivers/scsi/scsi_transport_iscsi.c | 26 +++++++++++++++++++++++--- 2 files changed, 27 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c index 0bc63a7ab41c..b5dd1caae5e9 100644 --- a/drivers/scsi/iscsi_tcp.c +++ b/drivers/scsi/iscsi_tcp.c @@ -887,6 +887,10 @@ iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) { struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); + struct iscsi_session *session = cls_session->dd_data; + + if (WARN_ON_ONCE(session->leadconn)) + return; iscsi_tcp_r2tpool_free(cls_session->dd_data); iscsi_session_teardown(cls_session); diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index ed8d9709b9b9..271afea654e2 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -2947,6 +2947,24 @@ iscsi_set_path(struct iscsi_transport *transport, struct iscsi_uevent *ev) return err; } +static int iscsi_session_has_conns(int sid) +{ + struct iscsi_cls_conn *conn; + unsigned long flags; + int found = 0; + + spin_lock_irqsave(&connlock, flags); + list_for_each_entry(conn, &connlist, conn_list) { + if (iscsi_conn_get_sid(conn) == sid) { + found = 1; + break; + } + } + spin_unlock_irqrestore(&connlock, flags); + + return found; +} + static int iscsi_set_iface_params(struct iscsi_transport *transport, struct iscsi_uevent *ev, uint32_t len) @@ -3524,10 +3542,12 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group) break; case ISCSI_UEVENT_DESTROY_SESSION: session = iscsi_session_lookup(ev->u.d_session.sid); - if (session) - transport->destroy_session(session); - else + if (!session) err = -EINVAL; + else if (iscsi_session_has_conns(ev->u.d_session.sid)) + err = -EBUSY; + else + transport->destroy_session(session); break; case ISCSI_UEVENT_UNBIND_SESSION: session = iscsi_session_lookup(ev->u.d_session.sid);