From nobody Fri May 3 18:30:10 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1529426462275798.2172378773759; Tue, 19 Jun 2018 09:41:02 -0700 (PDT) Received: from localhost ([::1]:43753 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fVJgj-0001XW-FM for importer@patchew.org; Tue, 19 Jun 2018 12:41:01 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56195) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fVJbs-0006Vv-2m for qemu-devel@nongnu.org; Tue, 19 Jun 2018 12:36:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fVJbn-0004rs-5z for qemu-devel@nongnu.org; Tue, 19 Jun 2018 12:36:00 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:59496 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fVJbm-0004qm-Vq for qemu-devel@nongnu.org; Tue, 19 Jun 2018 12:35:55 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2789F81A4EA8 for ; Tue, 19 Jun 2018 16:35:54 +0000 (UTC) Received: from t460.redhat.com (unknown [10.33.36.56]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2AFBD7C2C; Tue, 19 Jun 2018 16:35:52 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Date: Tue, 19 Jun 2018 17:35:52 +0100 Message-Id: <20180619163552.18206-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 19 Jun 2018 16:35:54 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 19 Jun 2018 16:35:54 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'berrange@redhat.com' RCPT:'' Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v2] migration: fix crash in when incoming client channel setup fails X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Dr. David Alan Gilbert" , Juan Quintela Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" The way we determine if we can start the incoming migration was changed to use migration_has_all_channels() in: commit 428d89084c709e568f9cd301c2f6416a54c53d6d Author: Juan Quintela Date: Mon Jul 24 13:06:25 2017 +0200 migration: Create migration_has_all_channels This method in turn calls multifd_recv_all_channels_created() which is hardcoded to always return 'true' when multifd is not in use. This is a latent bug... ...activated in in a following commit where that return result ends up acting as the flag to indicate whether it is possible to start processing the migration: commit 36c2f8be2c4eb0003ac77a14910842b7ddd7337e Author: Juan Quintela Date: Wed Mar 7 08:40:52 2018 +0100 migration: Delay start of migration main routines This means that if channel initialization fails with normal migration, it'll never notice and attempt to start the incoming migration regardless and crash on a NULL pointer. This can be seen, for example, if a client connects to a server requiring TLS, but has an invalid x509 certificate: qemu-system-x86_64: The certificate hasn't got a known issuer qemu-system-x86_64: migration/migration.c:386: process_incoming_migration_c= o: Assertion `mis->from_src_file' failed. #0 0x00007fffebd24f2b in raise () at /lib64/libc.so.6 #1 0x00007fffebd0f561 in abort () at /lib64/libc.so.6 #2 0x00007fffebd0f431 in _nl_load_domain.cold.0 () at /lib64/libc.so.6 #3 0x00007fffebd1d692 in () at /lib64/libc.so.6 #4 0x0000555555ad027e in process_incoming_migration_co (opaque=3D) at migration/migration.c:386 #5 0x0000555555c45e8b in coroutine_trampoline (i0=3D, i1= =3D) at util/coroutine-ucontext.c:116 #6 0x00007fffebd3a6a0 in __start_context () at /lib64/libc.so.6 #7 0x0000000000000000 in () To handle the non-multifd case, we check whether mis->from_src_file is non-NULL. With this in place, the migration server drops the rejected client and stays around waiting for another, hopefully valid, client to arrive. Signed-off-by: Daniel P. Berrang=C3=A9 Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela --- Changed in v2: - Clarify exactly when it broke - Clarify that we expect the server to stay active migration/migration.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/migration/migration.c b/migration/migration.c index e1eaa97df4..38ad818b23 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -518,11 +518,12 @@ void migration_ioc_process_incoming(QIOChannel *ioc) */ bool migration_has_all_channels(void) { + MigrationIncomingState *mis =3D migration_incoming_get_current(); bool all_channels; =20 all_channels =3D multifd_recv_all_channels_created(); =20 - return all_channels; + return all_channels && mis->from_src_file !=3D NULL; } =20 /* --=20 2.17.0