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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0ABC2C433FE for ; Mon, 15 Nov 2021 23:42:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED2A561AFF for ; Mon, 15 Nov 2021 23:42:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355698AbhKOXoB (ORCPT ); Mon, 15 Nov 2021 18:44:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:45212 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344059AbhKOTXM (ORCPT ); Mon, 15 Nov 2021 14:23:12 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4711463454; Mon, 15 Nov 2021 18:51:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637002266; bh=blodhIHFC8tOY9X//jl/GQPqkYAtWROkyMRhJtL8LNk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eMXd698zDzC/3JQYfQOXt79+0ziVoVcK3o+sNthqguQqcALd16bfaIqvafjpigN6g prbI9M6l7hAfhsLHTTZALaZgMUUSP8h6rTUaTQ13Wyp/5NhSfWZ1FNje6WnX2xTSwX sC4ZoIzu0ZeQyyzGSp++pHPiel0ZG0lTHrgOSyJQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Quentin Monnet , Andrii Nakryiko , Sasha Levin Subject: [PATCH 5.15 502/917] bpftool: Avoid leaking the JSON writer prepared for program metadata Date: Mon, 15 Nov 2021 17:59:57 +0100 Message-Id: <20211115165445.790114514@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165428.722074685@linuxfoundation.org> References: <20211115165428.722074685@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Quentin Monnet [ Upstream commit e89ef634f81c9d90e1824ab183721f3b361472e6 ] Bpftool creates a new JSON object for writing program metadata in plain text mode, regardless of metadata being present or not. Then this writer is freed if any metadata has been found and printed, but it leaks otherwise. We cannot destroy the object unconditionally, because the destructor prints an undesirable line break. Instead, make sure the writer is created only after we have found program metadata to print. Found with valgrind. Fixes: aff52e685eb3 ("bpftool: Support dumping metadata") Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211022094743.11052-1-quentin@isovalent.com Signed-off-by: Sasha Levin --- tools/bpf/bpftool/prog.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 9c3e343b7d872..fe59404e87046 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -308,18 +308,12 @@ static void show_prog_metadata(int fd, __u32 num_maps) if (printed_header) jsonw_end_object(json_wtr); } else { - json_writer_t *btf_wtr = jsonw_new(stdout); + json_writer_t *btf_wtr; struct btf_dumper d = { .btf = btf, - .jw = btf_wtr, .is_plain_text = true, }; - if (!btf_wtr) { - p_err("jsonw alloc failed"); - goto out_free; - } - for (i = 0; i < vlen; i++, vsi++) { t_var = btf__type_by_id(btf, vsi->type); name = btf__name_by_offset(btf, t_var->name_off); @@ -329,6 +323,14 @@ static void show_prog_metadata(int fd, __u32 num_maps) if (!printed_header) { printf("\tmetadata:"); + + btf_wtr = jsonw_new(stdout); + if (!btf_wtr) { + p_err("jsonw alloc failed"); + goto out_free; + } + d.jw = btf_wtr, + printed_header = true; } -- 2.33.0