From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:36176) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hEv6j-0002h9-0m for qemu-devel@nongnu.org; Fri, 12 Apr 2019 08:16:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hEv6i-0004Va-63 for qemu-devel@nongnu.org; Fri, 12 Apr 2019 08:16:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62442) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hEv6h-0004VM-W2 for qemu-devel@nongnu.org; Fri, 12 Apr 2019 08:16:36 -0400 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Fri, 12 Apr 2019 13:16:22 +0100 Message-Id: <20190412121626.19829-2-berrange@redhat.com> In-Reply-To: <20190412121626.19829-1-berrange@redhat.com> References: <20190412121626.19829-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v2 1/5] linux-user: avoid string truncation warnings in uname field copying List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Laurent Vivier , Riku Voipio , Gerd Hoffmann , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= In file included from /usr/include/string.h:494, from include/qemu/osdep.h:101, from linux-user/uname.c:20: In function =E2=80=98strncpy=E2=80=99, inlined from =E2=80=98sys_uname=E2=80=99 at linux-user/uname.c:94:3: /usr/include/bits/string_fortified.h:106:10: warning: =E2=80=98__builtin_= strncpy=E2=80=99 output may be truncated copying 64 bytes from a string o= f 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. Berrang=C3=A9 --- linux-user/uname.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/linux-user/uname.c b/linux-user/uname.c index 313b79dbad..3dff33effe 100644 --- a/linux-user/uname.c +++ b/linux-user/uname.c @@ -73,7 +73,7 @@ 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); \ + memcpy((dest), (src), MIN(sizeof(src), __NEW_UTS_LEN)); \ (dest)[__NEW_UTS_LEN] =3D '\0'; \ } while (0) =20 --=20 2.20.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4EF0C10F0E for ; Fri, 12 Apr 2019 12:21:48 +0000 (UTC) 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.kernel.org (Postfix) with ESMTPS id B0F982077C for ; Fri, 12 Apr 2019 12:21:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B0F982077C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:35537 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hEvBj-0006Md-Tk for qemu-devel@archiver.kernel.org; Fri, 12 Apr 2019 08:21:47 -0400 Received: from eggs.gnu.org ([209.51.188.92]:36176) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hEv6j-0002h9-0m for qemu-devel@nongnu.org; Fri, 12 Apr 2019 08:16:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hEv6i-0004Va-63 for qemu-devel@nongnu.org; Fri, 12 Apr 2019 08:16:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62442) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hEv6h-0004VM-W2 for qemu-devel@nongnu.org; Fri, 12 Apr 2019 08:16:36 -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 55548C05D3F5; Fri, 12 Apr 2019 12:16:35 +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 813FF5D9CC; Fri, 12 Apr 2019 12:16:33 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Date: Fri, 12 Apr 2019 13:16:22 +0100 Message-Id: <20190412121626.19829-2-berrange@redhat.com> In-Reply-To: <20190412121626.19829-1-berrange@redhat.com> References: <20190412121626.19829-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" 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 [10.5.110.32]); Fri, 12 Apr 2019 12:16:35 +0000 (UTC) Content-Transfer-Encoding: quoted-printable 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 1/5] 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 , Gerd Hoffmann Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Message-ID: <20190412121622.9OPPnHUCX4PE36Q8zYXTRxDEwbU1r6sdsUywyZRlVtE@z> In file included from /usr/include/string.h:494, from include/qemu/osdep.h:101, from linux-user/uname.c:20: In function =E2=80=98strncpy=E2=80=99, inlined from =E2=80=98sys_uname=E2=80=99 at linux-user/uname.c:94:3: /usr/include/bits/string_fortified.h:106:10: warning: =E2=80=98__builtin_= strncpy=E2=80=99 output may be truncated copying 64 bytes from a string o= f 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. Berrang=C3=A9 --- linux-user/uname.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/linux-user/uname.c b/linux-user/uname.c index 313b79dbad..3dff33effe 100644 --- a/linux-user/uname.c +++ b/linux-user/uname.c @@ -73,7 +73,7 @@ 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); \ + memcpy((dest), (src), MIN(sizeof(src), __NEW_UTS_LEN)); \ (dest)[__NEW_UTS_LEN] =3D '\0'; \ } while (0) =20 --=20 2.20.1