From nobody Wed Oct 1 02:39:10 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1545162644680298.99076031150435; Tue, 18 Dec 2018 11:50:44 -0800 (PST) Received: from localhost ([::1]:55631 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZJdJ-0000xN-61 for importer@patchew.org; Tue, 18 Dec 2018 12:58:17 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33931) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZJZW-0006mG-Hn for qemu-devel@nongnu.org; Tue, 18 Dec 2018 12:54:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gZJZU-0006cu-ER for qemu-devel@nongnu.org; Tue, 18 Dec 2018 12:54:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38288) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gZJZM-0006MJ-Rq; Tue, 18 Dec 2018 12:54:13 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DDE1FC0BF2AA; Tue, 18 Dec 2018 17:54:11 +0000 (UTC) Received: from x1w.redhat.com (ovpn-204-92.brq.redhat.com [10.40.204.92]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 693DD101963A; Tue, 18 Dec 2018 17:53:28 +0000 (UTC) From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= To: qemu-devel@nongnu.org Date: Tue, 18 Dec 2018 18:51:22 +0100 Message-Id: <20181218175122.3229-6-philmd@redhat.com> In-Reply-To: <20181218175122.3229-1-philmd@redhat.com> References: <20181218175122.3229-1-philmd@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Tue, 18 Dec 2018 17:54:12 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3 5/5] migration: Use strnlen() for fixed-size string X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Michael S. Tsirkin" , Jeff Cody , Ben Pye , qemu-block@nongnu.org, Juan Quintela , David Hildenbrand , Markus Armbruster , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Liu Yuan , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Thomas Huth , Stefan Weil , Howard Spoelstra , "Dr. David Alan Gilbert" , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= , Paolo Bonzini , David Gibson , Kevin Wolf , Max Reitz , 1803872@bugs.launchpad.net, Igor Mammedov Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" GCC 8 introduced the -Wstringop-overflow, which detect buffer overflow by string-modifying functions declared in , such strncpy(), used in global_state_store_running(). Since the global_state.runstate does not necessarily contains a terminating NUL character, We had to use the QEMU_NONSTRING attribute. The GCC manual says about the nonstring attribute: However, when the array is declared with the attribute the call to strlen is diagnosed because when the array doesn=E2=80=99t contain a NUL-terminated string the call is undefined. [...] In addition, calling strnlen and strndup with such arrays is safe provided a suitable bound is specified, and not diagnosed. GCC indeed found an incorrect use of strlen(), because this array is loaded by VMSTATE_BUFFER(runstate, GlobalState) then parsed using qapi_enum_parse which does not get the buffer length. Use strnlen() which returns sizeof(s->runstate) if the array is not NUL-terminated. This fixes: CC migration/global_state.o qemu/migration/global_state.c: In function 'global_state_pre_save': qemu/migration/global_state.c:109:15: error: 'strlen' argument 1 declared= attribute 'nonstring' [-Werror=3Dstringop-overflow=3D] s->size =3D strlen((char *)s->runstate) + 1; ^~~~~~~~~~~~~~~~~~~~~~~~~~~ qemu/migration/global_state.c:24:13: note: argument 'runstate' declared h= ere uint8_t runstate[100] QEMU_NONSTRING; ^~~~~~~~ cc1: all warnings being treated as errors make: *** [qemu/rules.mak:69: migration/global_state.o] Error 1 Signed-off-by: Philippe Mathieu-Daud=C3=A9 --- migration/global_state.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/migration/global_state.c b/migration/global_state.c index 6e19333422..c19030ef62 100644 --- a/migration/global_state.c +++ b/migration/global_state.c @@ -106,7 +106,7 @@ static int global_state_pre_save(void *opaque) GlobalState *s =3D opaque; =20 trace_migrate_global_state_pre_save((char *)s->runstate); - s->size =3D strlen((char *)s->runstate) + 1; + s->size =3D strnlen((char *)s->runstate, sizeof(s->runstate)) + 1; =20 return 0; } --=20 2.17.2