From patchwork Wed Jul 31 09:19:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 11067379 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 DA83F1395 for ; Wed, 31 Jul 2019 09:23:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C48B8288C6 for ; Wed, 31 Jul 2019 09:23:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B8795288DD; Wed, 31 Jul 2019 09:23:33 +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 TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5385326E54 for ; Wed, 31 Jul 2019 09:23:33 +0000 (UTC) Received: from localhost ([::1]:39242 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hskpY-0002wf-P0 for patchwork-qemu-devel@patchwork.kernel.org; Wed, 31 Jul 2019 05:23:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59919) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hskpB-00029E-7G for qemu-devel@nongnu.org; Wed, 31 Jul 2019 05:23:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hskpA-0000Zq-0p for qemu-devel@nongnu.org; Wed, 31 Jul 2019 05:23:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48870) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hskp9-0000Yl-Oy for qemu-devel@nongnu.org; Wed, 31 Jul 2019 05:23:07 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1954881DF1; Wed, 31 Jul 2019 09:23:07 +0000 (UTC) Received: from localhost.localdomain (ovpn-116-38.phx2.redhat.com [10.3.116.38]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 623F85C1B5; Wed, 31 Jul 2019 09:22:56 +0000 (UTC) From: P J P To: Jason Wang Date: Wed, 31 Jul 2019 14:49:33 +0530 Message-Id: <20190731091933.17363-1-ppandit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Wed, 31 Jul 2019 09:23:07 +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 v5] net: tap: replace snprintf with g_strdup_printf calls X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Stefan Hajnoczi , Li Qiang , =?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= , QEMU Developers , Prasad J Pandit Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Prasad J Pandit When invoking qemu-bridge-helper in 'net_bridge_run_helper', instead of using fixed sized buffers, use dynamically allocated ones initialised and returned by g_strdup_printf(). If bridge name 'br_buf' is undefined, pass empty string ("") to g_strdup_printf() in its place, to avoid printing "(null)" string. Signed-off-by: Prasad J Pandit Reviewed-by: Markus Armbruster --- net/tap.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) Update v5: add commit message about conditional 'br_buf' argument -> https://lists.gnu.org/archive/html/qemu-devel/2019-07/msg06397.html diff --git a/net/tap.c b/net/tap.c index e8aadd8d4b..fc38029f41 100644 --- a/net/tap.c +++ b/net/tap.c @@ -498,9 +498,9 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, } if (pid == 0) { int open_max = sysconf(_SC_OPEN_MAX), i; - char fd_buf[6+10]; - char br_buf[6+IFNAMSIZ] = {0}; - char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15]; + char *fd_buf = NULL; + char *br_buf = NULL; + char *helper_cmd = NULL; for (i = 3; i < open_max; i++) { if (i != sv[1]) { @@ -508,17 +508,17 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, } } - snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]); + fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]); if (strrchr(helper, ' ') || strrchr(helper, '\t')) { /* assume helper is a command */ if (strstr(helper, "--br=") == NULL) { - snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); + br_buf = g_strdup_printf("%s%s", "--br=", bridge); } - snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s", - helper, "--use-vnet", fd_buf, br_buf); + helper_cmd = g_strdup_printf("%s %s %s %s", helper, + "--use-vnet", fd_buf, br_buf ? br_buf : ""); parg = args; *parg++ = (char *)"sh"; @@ -527,10 +527,11 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, *parg++ = NULL; execv("/bin/sh", args); + g_free(helper_cmd); } else { /* assume helper is just the executable path name */ - snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); + br_buf = g_strdup_printf("%s%s", "--br=", bridge); parg = args; *parg++ = (char *)helper; @@ -541,6 +542,8 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, execv(helper, args); } + g_free(fd_buf); + g_free(br_buf); _exit(1); } else {