From patchwork Tue Feb 28 09:29:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 13154582 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 D01E1C64ED6 for ; Tue, 28 Feb 2023 09:30:45 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pWwJB-0005FM-1M; Tue, 28 Feb 2023 04:30:05 -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 1pWwJ3-0005EP-OG for qemu-devel@nongnu.org; Tue, 28 Feb 2023 04:29:59 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pWwJ0-0001QO-UX for qemu-devel@nongnu.org; Tue, 28 Feb 2023 04:29:57 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677576593; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=dw31KU5kTtqYyIJOoZXgONAgLFqc+q7Xq8bJiEzcSak=; b=UAAkLMgYoDtZiQciD9d1SOZmInzYMCwDw44tBmImkJu2eutHWB7UX41Bnvc2oG9vUYaEou lK06FiJxZfrsfPYvj7qGOiuZ4vcA3Uz/YJhk7AQ3L8CDIIuw8agKP8j8IVBBXI5QBFJGp1 wAHgbXB60d8C5XopSq5IFFbyNr6Cda4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-385--l_5CPHEO-WNsuUW7TNpWg-1; Tue, 28 Feb 2023 04:29:52 -0500 X-MC-Unique: -l_5CPHEO-WNsuUW7TNpWg-1 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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id B9C1285A5B1; Tue, 28 Feb 2023 09:29:51 +0000 (UTC) Received: from laptop.redhat.com (unknown [10.45.224.134]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7D9672026D4B; Tue, 28 Feb 2023 09:29:49 +0000 (UTC) From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, dgilbert@redhat.com, quintela@redhat.com, qemu-devel@nongnu.org, rjones@redhat.com, marcandre.lureau@redhat.com Cc: armbru@redhat.com, philmd@linaro.org, berrange@redhat.com Subject: [PATCH v4] test-vmstate: fix bad GTree usage, use-after-free Date: Tue, 28 Feb 2023 10:29:44 +0100 Message-Id: <20230228092944.341317-1-eric.auger@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=eric.auger@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 According to g_tree_foreach() documentation: "The tree may not be modified while iterating over it (you can't add/remove items)." compare_trees()/diff_tree() fail to respect this rule. Historically GLib2 used a slice allocator for the GTree APIs which did not immediately release the memory back to the system allocator. As a result QEMU's use-after-free bug was not visible. With GLib > 2.75.3 however, GLib2 has switched to using malloc and now a SIGSEGV can be observed while running test-vmstate. Get rid of the node removal within the tree traversal. Also check the trees have the same number of nodes before the actual diff. Fixes: 9a85e4b8f6 ("migration: Support gtree migration") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1518 Signed-off-by: Marc-André Lureau Signed-off-by: Eric Auger Reported-by: Richard W.M. Jones Tested-by: Richard W.M. Jones Reviewed-by: Richard W.M. Jones Reviewed-by: Daniel P. Berrangé Reviewed-by: Juan Quintela --- v3 -> v4: - Adopt Daniel's wording and add his R-b v2 -> v3: - Enhance the commit message with Rich's explanations - Add Roch's T-b and R-b v1 -> v2: - respin of Marc-André's patch from Aug 2020, which can be found at https://lore.kernel.org/qemu-devel/20200827161826.1165971-1-marcandre.lureau@redhat.com/ This fell through the cracks and now we hit a SIGSEGV --- tests/unit/test-vmstate.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/tests/unit/test-vmstate.c b/tests/unit/test-vmstate.c index 79357b29ca..0b7d5ecd68 100644 --- a/tests/unit/test-vmstate.c +++ b/tests/unit/test-vmstate.c @@ -1073,7 +1073,6 @@ static gboolean diff_tree(gpointer key, gpointer value, gpointer data) struct match_node_data d = {tp->tree2, key, value}; g_tree_foreach(tp->tree2, tp->match_node, &d); - g_tree_remove(tp->tree1, key); return false; } @@ -1082,9 +1081,9 @@ static void compare_trees(GTree *tree1, GTree *tree2, { struct tree_cmp_data tp = {tree1, tree2, function}; + assert(g_tree_nnodes(tree1) == g_tree_nnodes(tree2)); g_tree_foreach(tree1, diff_tree, &tp); - assert(g_tree_nnodes(tree1) == 0); - assert(g_tree_nnodes(tree2) == 0); + g_tree_destroy(g_tree_ref(tree1)); } static void diff_domain(TestGTreeDomain *d1, TestGTreeDomain *d2)