From patchwork Tue Nov 21 17:34:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 13463420 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 C7B0EC61D85 for ; Tue, 21 Nov 2023 17:35:18 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r5Udt-0003gF-BJ; Tue, 21 Nov 2023 12:34:33 -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 1r5Uds-0003fu-1D for qemu-devel@nongnu.org; Tue, 21 Nov 2023 12:34:32 -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 1r5Udo-0008Ix-Tt for qemu-devel@nongnu.org; Tue, 21 Nov 2023 12:34:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1700588066; 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=K7qNnSKJxOZantk4zTpYBHMaq49b+c+NbuYszzcGHU4=; b=dNFMm4BPLATDWSvqEPSANULwBFiaCi45RGb7w+sDee1C+qpf12Vy2TSjbCeMgU7gjsUOh4 yCXNXvTyz7cdUAoFt/7SCj9/DEqckzaopr0BM0BTzJ6EMuGJjdaU5Qzaz6psQkNygo9DNW gGIZ5Kh2oP7wJC9GoPbnTBstSRHrpgs= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-517-xIWxVDC1MwK_mUWKLw-x9A-1; Tue, 21 Nov 2023 12:34:24 -0500 X-MC-Unique: xIWxVDC1MwK_mUWKLw-x9A-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9BFE21C060CE; Tue, 21 Nov 2023 17:34:24 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.194.112]) by smtp.corp.redhat.com (Postfix) with ESMTP id AA84A1C060AE; Tue, 21 Nov 2023 17:34:23 +0000 (UTC) From: Kevin Wolf To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, thuth@redhat.com, armbru@redhat.com, philmd@linaro.org, peter.maydell@linaro.org Subject: [PATCH for-8.2 1/2] qdev: Fix crash in array property getter Date: Tue, 21 Nov 2023 18:34:15 +0100 Message-ID: <20231121173416.346610-2-kwolf@redhat.com> In-Reply-To: <20231121173416.346610-1-kwolf@redhat.com> References: <20231121173416.346610-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.129.124; 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 Passing an uninitialised list to visit_start_list() happens to work for the QObject output visitor because it treats the pointer as an opaque value and never dereferences it, but the string output visitor expects a valid list to check if it has more than one element. The existing code crashes with the string output visitor if the uninitialised value is non-NULL. Passing an explicit NULL would fix the crash, but still result in wrong output. Rework get_prop_array() so that it conforms to the expectations that the string output visitor has. This includes building a real list first and using visit_next_list() to iterate it. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1993 Reported-by: Thomas Huth Signed-off-by: Kevin Wolf Tested-by: Dan Hoffman --- hw/core/qdev-properties.c | 33 ++++++++++++++++++++++++++------- 1 file changed, 26 insertions(+), 7 deletions(-) diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c index 91632f7be9..840006e953 100644 --- a/hw/core/qdev-properties.c +++ b/hw/core/qdev-properties.c @@ -689,23 +689,36 @@ static void get_prop_array(Object *obj, Visitor *v, const char *name, Property *prop = opaque; uint32_t *alenptr = object_field_prop_ptr(obj, prop); void **arrayptr = (void *)obj + prop->arrayoffset; - char *elem = *arrayptr; - GenericList *list; - const size_t list_elem_size = sizeof(*list) + prop->arrayfieldsize; + char *elemptr = *arrayptr; + ArrayElementList *list = NULL, *elem; + ArrayElementList **tail = &list; + const size_t size = sizeof(*list); int i; bool ok; - if (!visit_start_list(v, name, &list, list_elem_size, errp)) { + /* At least the string output visitor needs a real list */ + for (i = 0; i < *alenptr; i++) { + elem = g_new0(ArrayElementList, 1); + elem->value = elemptr; + elemptr += prop->arrayfieldsize; + + *tail = elem; + tail = &elem->next; + } + + if (!visit_start_list(v, name, (GenericList **) &list, size, errp)) { return; } - for (i = 0; i < *alenptr; i++) { - Property elem_prop = array_elem_prop(obj, prop, name, elem); + elem = list; + while (elem) { + Property elem_prop = array_elem_prop(obj, prop, name, elem->value); prop->arrayinfo->get(obj, v, NULL, &elem_prop, errp); if (*errp) { goto out_obj; } - elem += prop->arrayfieldsize; + elem = (ArrayElementList *) visit_next_list(v, (GenericList*) elem, + size); } /* visit_check_list() can only fail for input visitors */ @@ -714,6 +727,12 @@ static void get_prop_array(Object *obj, Visitor *v, const char *name, out_obj: visit_end_list(v, (void**) &list); + + while (list) { + elem = list; + list = elem->next; + g_free(elem); + } } static void default_prop_array(ObjectProperty *op, const Property *prop)