From patchwork Mon Jul 29 08:33:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 1138250 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 TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 45xtNQ2Wflz9s3l for ; Mon, 29 Jul 2019 18:37:26 +1000 (AEST) Received: from localhost ([::1]:50490 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hs19o-0000Q5-EQ for incoming@patchwork.ozlabs.org; Mon, 29 Jul 2019 04:37:24 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48056) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hs16Z-0004VL-9C for qemu-devel@nongnu.org; Mon, 29 Jul 2019 04:34:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hs16X-0003Ik-73 for qemu-devel@nongnu.org; Mon, 29 Jul 2019 04:34:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45566) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hs16V-0003Hy-5f for qemu-devel@nongnu.org; Mon, 29 Jul 2019 04:34:00 -0400 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 617BC3082133; Mon, 29 Jul 2019 08:33:58 +0000 (UTC) Received: from jason-ThinkPad-T430s.redhat.com (ovpn-12-203.pek2.redhat.com [10.72.12.203]) by smtp.corp.redhat.com (Postfix) with ESMTP id B790410190AA; Mon, 29 Jul 2019 08:33:56 +0000 (UTC) From: Jason Wang To: qemu-devel@nongnu.org, peter.maydell@linaro.org Date: Mon, 29 Jul 2019 16:33:45 +0800 Message-Id: <1564389226-4489-5-git-send-email-jasowang@redhat.com> In-Reply-To: <1564389226-4489-1-git-send-email-jasowang@redhat.com> References: <1564389226-4489-1-git-send-email-jasowang@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 [10.5.110.42]); Mon, 29 Jul 2019 08:33:58 +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] [PULL 4/5] 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: Jason Wang , Prasad J Pandit Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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(). Signed-off-by: Prasad J Pandit Reviewed-by: Li Qiang Reviewed-by: Daniel P. Berrangé Signed-off-by: Jason Wang --- net/tap.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/net/tap.c b/net/tap.c index e8aadd8..fc38029 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 {