From mboxrd@z Thu Jan 1 00:00:00 1970 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 37C88C636D6 for ; Thu, 23 Feb 2023 18:52:41 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pVGhF-0006jm-HA; Thu, 23 Feb 2023 13:52:01 -0500 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 1pVGhD-0006ij-Do for qemu-devel@nongnu.org; Thu, 23 Feb 2023 13:51:59 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pVGhB-0002q1-D9 for qemu-devel@nongnu.org; Thu, 23 Feb 2023 13:51:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677178315; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yuWWuA2ClE7EGvnZOUFjsvYflGX+2qlq70Du1Ss8tvs=; b=AfM6cWZEkWDvehVy/t98E0c6G7LKbCUqWI9KKjni2oBxDOSsDxGJfs3WdGVbiyNCyRuq3K BDBBX41vM69s7y/Go9rPit1cHTdDa/CYY32tOaoMkiofgTt/oc3pjlR2NRrEadCTgf0vc+ eTDNG6MgMbpNsW1Rew6EdmdYJBm+sdc= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-546-6ppaI173PZuZRy0HyqcTBg-1; Thu, 23 Feb 2023 13:51:53 -0500 X-MC-Unique: 6ppaI173PZuZRy0HyqcTBg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 767F23C0D843; Thu, 23 Feb 2023 18:51:53 +0000 (UTC) Received: from merkur.redhat.com (unknown [10.39.192.128]) by smtp.corp.redhat.com (Postfix) with ESMTP id C25B21121314; Thu, 23 Feb 2023 18:51:52 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Subject: [PULL 02/29] mirror: Fix access of uninitialised fields during start Date: Thu, 23 Feb 2023 19:51:19 +0100 Message-Id: <20230223185146.306454-3-kwolf@redhat.com> In-Reply-To: <20230223185146.306454-1-kwolf@redhat.com> References: <20230223185146.306454-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, 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 Precedence: list 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 bdrv_mirror_top_pwritev() accesses the job object when active mirroring is enabled. It disables this code during early initialisation while s->job isn't set yet. However, s->job is still set way too early when the job object isn't fully initialised. For example, &s->ops_in_flight isn't initialised yet and the in_flight bitmap doesn't exist yet. This causes crashes when a write request comes in too early. Move the assignment of s->job to when the mirror job is actually fully initialised to make sure that the mirror_top driver doesn't access it too early. Signed-off-by: Kevin Wolf Message-Id: <20230203152202.49054-3-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito Reviewed-by: Vladimir Sementsov-Ogievskiy Signed-off-by: Kevin Wolf --- block/mirror.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/block/mirror.c b/block/mirror.c index ab326b67c9..fbbb4f619e 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -896,6 +896,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp) { MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job); BlockDriverState *bs = s->mirror_top_bs->backing->bs; + MirrorBDSOpaque *mirror_top_opaque = s->mirror_top_bs->opaque; BlockDriverState *target_bs = blk_bs(s->target); bool need_drain = true; BlockDeviceIoStatus iostatus; @@ -985,6 +986,12 @@ static int coroutine_fn mirror_run(Job *job, Error **errp) } } + /* + * Only now the job is fully initialised and mirror_top_bs should start + * accessing it. + */ + mirror_top_opaque->job = s; + assert(!s->dbi); s->dbi = bdrv_dirty_iter_new(s->dirty_bitmap); for (;;) { @@ -1704,7 +1711,6 @@ static BlockJob *mirror_start_job( if (!s) { goto fail; } - bs_opaque->job = s; /* The block job now has a reference to this node */ bdrv_unref(mirror_top_bs); -- 2.39.2