From patchwork Tue Feb 28 09:03:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 13154541 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 67051C64ED6 for ; Tue, 28 Feb 2023 09:04:48 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pWvu3-0006Lk-O7; Tue, 28 Feb 2023 04:04:07 -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 1pWvu0-0006DT-IW for qemu-devel@nongnu.org; Tue, 28 Feb 2023 04:04:06 -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 1pWvty-0004zi-QZ for qemu-devel@nongnu.org; Tue, 28 Feb 2023 04:04:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677575042; 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=6Xyzasnn92Bhcu5FsK2qLFApuAiVuAAyYIL5NJn3p34=; b=JMMvdyr6qcoeA/QLVht8/v342BQ2KJ3Ey+fdI1FVfow7HR1yC7S8rYkNc+XpLVvRUv+65w bfB7TuU7shLFA/a0f3+2zZIiIHjbrxout7PTFX48Y0RX+YOlnNdazKS0IGKeC9Fzv/S7ox zOSKsbt6p+Bq6t6I6cWZakBL4dMPujs= 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-152-GADYZaUiPOKGBd1CYw_-KA-1; Tue, 28 Feb 2023 04:04:00 -0500 X-MC-Unique: GADYZaUiPOKGBd1CYw_-KA-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 580603C21C2E; Tue, 28 Feb 2023 09:04:00 +0000 (UTC) Received: from laptop.redhat.com (unknown [10.45.224.134]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2079C2026D4B; Tue, 28 Feb 2023 09:03:57 +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 v3] test-vmstate: fix bad GTree usage, use-after-free Date: Tue, 28 Feb 2023 10:03:52 +0100 Message-Id: <20230228090352.339466-1-eric.auger@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Received-SPF: pass client-ip=170.10.133.124; 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)." Since glib2 has removed its custom slice allocator and has switched to using system malloc, a SIGSEGV can be observed while running test-vmstate. With glibc + MALLOC_PERTURB_, malloc is able to detect this kind of bugs. The relevant glib2 change that causes the problem is: https://gitlab.gnome.org/GNOME/glib/-/commit/45b5a6c1e56d5b73cc5ed798ef59a5601e56c170 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 --- v2 -> v3: - Enhance the commit message with Rich's explanations 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)