From patchwork Mon Apr 29 19:14:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Sementsov-Ogievskiy X-Patchwork-Id: 13647573 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E4D16C4345F for ; Mon, 29 Apr 2024 19:16:08 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1s1WT3-00074o-Cy; Mon, 29 Apr 2024 15:15:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1s1WT0-000748-9Y for qemu-devel@nongnu.org; Mon, 29 Apr 2024 15:15:11 -0400 Received: from forwardcorp1b.mail.yandex.net ([2a02:6b8:c02:900:1:45:d181:df01]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1s1WSq-0004y6-0r for qemu-devel@nongnu.org; Mon, 29 Apr 2024 15:15:10 -0400 Received: from mail-nwsmtp-smtp-corp-canary-81.sas.yp-c.yandex.net (mail-nwsmtp-smtp-corp-canary-81.sas.yp-c.yandex.net [IPv6:2a02:6b8:c10:3196:0:640:fabe:0]) by forwardcorp1b.mail.yandex.net (Yandex) with ESMTPS id BC10C60CC8; Mon, 29 Apr 2024 22:14:55 +0300 (MSK) Received: from vsementsov-lin.. (unknown [2a02:6b8:b081:b739::1:30]) by mail-nwsmtp-smtp-corp-canary-81.sas.yp-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id hEWuLX0IkKo0-jRXyXKDB; Mon, 29 Apr 2024 22:14:54 +0300 Precedence: bulk X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1714418094; bh=EjG01w0ZewrQrMMGogXRmrmdHkTzWdbk9YqLV9bWgLM=; h=Message-Id:Date:In-Reply-To:Cc:Subject:References:To:From; b=rCk/jeQkkqnvHpzYKB/c4fh+8FRAtZiozAGZWTvNmYJp4UCDNsTvLyxcdkQVpeYva Xx+tOUdMs7HtZIXe2wsoKgiUPqfHdJq8GshBc8Zv2Vg2HigP/cmymFRhLGNPUl1guf vJYfz6QisK+MCdqbyW5apyFgiHXg66stsfnYrsSk= Authentication-Results: mail-nwsmtp-smtp-corp-canary-81.sas.yp-c.yandex.net; dkim=pass header.i=@yandex-team.ru From: Vladimir Sementsov-Ogievskiy To: peterx@redhat.com, farosas@suse.de Cc: eblake@redhat.com, armbru@redhat.com, pbonzini@redhat.com, qemu-devel@nongnu.org, vsementsov@yandex-team.ru, yc-core@yandex-team.ru Subject: [PATCH v5 3/5] migration: process_incoming_migration_co(): fix reporting s->error Date: Mon, 29 Apr 2024 22:14:24 +0300 Message-Id: <20240429191426.2327225-4-vsementsov@yandex-team.ru> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240429191426.2327225-1-vsementsov@yandex-team.ru> References: <20240429191426.2327225-1-vsementsov@yandex-team.ru> MIME-Version: 1.0 Received-SPF: pass client-ip=2a02:6b8:c02:900:1:45:d181:df01; envelope-from=vsementsov@yandex-team.ru; helo=forwardcorp1b.mail.yandex.net X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org It's bad idea to leave critical section with error object freed, but s->error still set, this theoretically may lead to use-after-free crash. Let's avoid it. Signed-off-by: Vladimir Sementsov-Ogievskiy --- migration/migration.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 0d26db47f7..58fd5819bc 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -732,9 +732,19 @@ static void process_incoming_migration_bh(void *opaque) migration_incoming_state_destroy(); } +static void migrate_error_free(MigrationState *s) +{ + QEMU_LOCK_GUARD(&s->error_mutex); + if (s->error) { + error_free(s->error); + s->error = NULL; + } +} + static void coroutine_fn process_incoming_migration_co(void *opaque) { + MigrationState *s = migrate_get_current(); MigrationIncomingState *mis = migration_incoming_get_current(); PostcopyState ps; int ret; @@ -779,11 +789,9 @@ process_incoming_migration_co(void *opaque) } if (ret < 0) { - MigrationState *s = migrate_get_current(); - if (migrate_has_error(s)) { WITH_QEMU_LOCK_GUARD(&s->error_mutex) { - error_report_err(s->error); + error_report_err(error_copy(s->error)); } } error_report("load of migration failed: %s", strerror(-ret)); @@ -801,6 +809,7 @@ fail: MIGRATION_STATUS_FAILED); migration_incoming_state_destroy(); + migrate_error_free(s); exit(EXIT_FAILURE); } @@ -1433,15 +1442,6 @@ bool migrate_has_error(MigrationState *s) return qatomic_read(&s->error); } -static void migrate_error_free(MigrationState *s) -{ - QEMU_LOCK_GUARD(&s->error_mutex); - if (s->error) { - error_free(s->error); - s->error = NULL; - } -} - static void migrate_fd_error(MigrationState *s, const Error *error) { assert(s->to_dst_file == NULL);