From patchwork Wed May 1 14:46:46 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: 10925195 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 831931398 for ; Wed, 1 May 2019 14:48:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 721F828847 for ; Wed, 1 May 2019 14:48:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 65213288FA; Wed, 1 May 2019 14:48:07 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id EBF1928847 for ; Wed, 1 May 2019 14:48:06 +0000 (UTC) Received: from localhost ([127.0.0.1]:60110 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hLqWk-0003Wm-1p for patchwork-qemu-devel@patchwork.kernel.org; Wed, 01 May 2019 10:48:06 -0400 Received: from eggs.gnu.org ([209.51.188.92]:54232) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hLqVe-0002fA-2j for qemu-devel@nongnu.org; Wed, 01 May 2019 10:47:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hLqVa-0001wS-DT for qemu-devel@nongnu.org; Wed, 01 May 2019 10:46:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35882) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hLqVa-0001vX-8R for qemu-devel@nongnu.org; Wed, 01 May 2019 10:46:54 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 98EF959451; Wed, 1 May 2019 14:46:50 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-112-28.ams2.redhat.com [10.36.112.28]) by smtp.corp.redhat.com (Postfix) with ESMTP id D657A85882; Wed, 1 May 2019 14:46:48 +0000 (UTC) From: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= To: qemu-devel@nongnu.org Date: Wed, 1 May 2019 15:46:46 +0100 Message-Id: <20190501144646.4851-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 01 May 2019 14:46:50 +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] linux-user: avoid string truncation warnings in uname 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 Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP In file included from /usr/include/string.h:494, from include/qemu/osdep.h:101, from linux-user/uname.c:20: In function ‘strncpy’, inlined from ‘sys_uname’ at linux-user/uname.c:94:3: /usr/include/bits/string_fortified.h:106:10: warning: ‘__builtin_strncpy’ output may be truncated copying 64 bytes from a string of length 64 [-Wstringop-truncation] 106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We don't care where the NUL terminator in the original uname field was. It suffices to copy the entire original field and simply force a NUL terminator at the end of the new field. Signed-off-by: Daniel P. Berrangé Reviewed-by: Philippe Mathieu-Daudé --- Changed in v2: - Always use sizeof() in preference to __NEW_UTS_LEN linux-user/uname.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/linux-user/uname.c b/linux-user/uname.c index 313b79dbad..1c05f95387 100644 --- a/linux-user/uname.c +++ b/linux-user/uname.c @@ -72,9 +72,8 @@ const char *cpu_to_uname_machine(void *cpu_env) #define COPY_UTSNAME_FIELD(dest, src) \ do { \ - /* __NEW_UTS_LEN doesn't include terminating null */ \ - (void) strncpy((dest), (src), __NEW_UTS_LEN); \ - (dest)[__NEW_UTS_LEN] = '\0'; \ + memcpy((dest), (src), MIN(sizeof(src), sizeof(dest))); \ + (dest)[sizeof(dest) - 1] = '\0'; \ } while (0) int sys_uname(struct new_utsname *buf)