From patchwork Fri Apr 12 12:16:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 1084670 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 44gcNJ6XPxz9s55 for ; Fri, 12 Apr 2019 22:17:36 +1000 (AEST) Received: from localhost ([127.0.0.1]:35463 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hEv7e-0002iz-PU for incoming@patchwork.ozlabs.org; Fri, 12 Apr 2019 08:17:34 -0400 Received: from eggs.gnu.org ([209.51.188.92]:36196) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hEv6l-0002he-Gd for qemu-devel@nongnu.org; Fri, 12 Apr 2019 08:16:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hEv6k-0004WN-JR for qemu-devel@nongnu.org; Fri, 12 Apr 2019 08:16:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37740) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hEv6k-0004W7-Cp for qemu-devel@nongnu.org; Fri, 12 Apr 2019 08:16:38 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B016930842B5; Fri, 12 Apr 2019 12:16:37 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-112-27.ams2.redhat.com [10.36.112.27]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9E1905D9CC; Fri, 12 Apr 2019 12:16:35 +0000 (UTC) From: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= To: qemu-devel@nongnu.org Date: Fri, 12 Apr 2019 13:16:23 +0100 Message-Id: <20190412121626.19829-3-berrange@redhat.com> In-Reply-To: <20190412121626.19829-1-berrange@redhat.com> References: <20190412121626.19829-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Fri, 12 Apr 2019 12:16:37 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 2/5] linux-user: avoid string truncation warnings in elf field copying 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: Riku Voipio , Laurent Vivier , Gerd Hoffmann Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" In file included from /usr/include/string.h:494, from include/qemu/osdep.h:101, from linux-user/elfload.c:2: In function ‘strncpy’, inlined from ‘fill_psinfo’ at linux-user/elfload.c:3208:12, inlined from ‘fill_note_info’ at linux-user/elfload.c:3390:5, inlined from ‘elf_core_dump’ at linux-user/elfload.c:3539:9: /usr/include/bits/string_fortified.h:106:10: warning: ‘__builtin_strncpy’ specified bound 16 equals destination size [-Wstringop-truncation] 106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We don't require the field to be NUL terminated, so can just copy the lower of the string length and the target field size using memcpy. Signed-off-by: Daniel P. Berrangé --- linux-user/elfload.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/linux-user/elfload.c b/linux-user/elfload.c index c1a26021f8..caa060f7b7 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -3180,6 +3180,7 @@ static int fill_psinfo(struct target_elf_prpsinfo *psinfo, const TaskState *ts) { char *base_filename; unsigned int i, len; + size_t pathlen; (void) memset(psinfo, 0, sizeof (*psinfo)); @@ -3201,12 +3202,9 @@ static int fill_psinfo(struct target_elf_prpsinfo *psinfo, const TaskState *ts) psinfo->pr_gid = getgid(); base_filename = g_path_get_basename(ts->bprm->filename); - /* - * Using strncpy here is fine: at max-length, - * this field is not NUL-terminated. - */ - (void) strncpy(psinfo->pr_fname, base_filename, - sizeof(psinfo->pr_fname)); + pathlen = strlen(base_filename) + 1; + pathlen = MIN(pathlen, sizeof(psinfo->pr_fname)); + memcpy(psinfo->pr_fname, base_filename, pathlen); g_free(base_filename); bswap_psinfo(psinfo);