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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 6BDA3C76186 for ; Wed, 24 Jul 2019 19:52:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3CBF02147A for ; Wed, 24 Jul 2019 19:52:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563997973; bh=m0fTq+hjHtyh+NTukjYK0o8EVFrit1Qv2qvErHTld2c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZFJlekW1JOqk+VELNfcLr8uF2V0VUT/CE+Nczl4ilHH/HfQ9P2E8R6gx9hLhwGF9b dVW68Hdeu720/rIMtytGGUNatIDBpf1kx+OPF/FUcnTc1D1O/InjDfYzLrWG1hXYfD 6Vm4OLRtieHYe3DXxdM0tVTr+l9958V1Z2s9n8nU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391796AbfGXTww (ORCPT ); Wed, 24 Jul 2019 15:52:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:34910 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391050AbfGXTwt (ORCPT ); Wed, 24 Jul 2019 15:52:49 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A600620665; Wed, 24 Jul 2019 19:52:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563997969; bh=m0fTq+hjHtyh+NTukjYK0o8EVFrit1Qv2qvErHTld2c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QGAACST2c85X6uRn6dmq/6tRaK5idferzGYMwBXqrsw0Ta7k2w9ArNuhtolaNHvei T0O2YpcvPsxNCYigK6msduaEqNUGDLDvL2c3SaZkBpfs63gvf1jedCbCkgvTjBX9Lu UsqXXlIbKHsiEXYpW8MRMRRb7RaCks2pZ58mcuMc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Petlan , Jiri Olsa , Quentin Monnet , Jakub Kicinski , Daniel Borkmann , Sasha Levin Subject: [PATCH 5.1 202/371] tools: bpftool: Fix json dump crash on powerpc Date: Wed, 24 Jul 2019 21:19:14 +0200 Message-Id: <20190724191739.875701494@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191724.382593077@linuxfoundation.org> References: <20190724191724.382593077@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit aa52bcbe0e72fac36b1862db08b9c09c4caefae3 ] Michael reported crash with by bpf program in json mode on powerpc: # bpftool prog -p dump jited id 14 [{ "name": "0xd00000000a9aa760", "insns": [{ "pc": "0x0", "operation": "nop", "operands": [null ] },{ "pc": "0x4", "operation": "nop", "operands": [null ] },{ "pc": "0x8", "operation": "mflr", Segmentation fault (core dumped) The code is assuming char pointers in format, which is not always true at least for powerpc. Fixing this by dumping the whole string into buffer based on its format. Please note that libopcodes code does not check return values from fprintf callback, but as per Jakub suggestion returning -1 on allocation failure so we do the best effort to propagate the error. Fixes: 107f041212c1 ("tools: bpftool: add JSON output for `bpftool prog dump jited *` command") Reported-by: Michael Petlan Signed-off-by: Jiri Olsa Reviewed-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- tools/bpf/bpftool/jit_disasm.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/tools/bpf/bpftool/jit_disasm.c b/tools/bpf/bpftool/jit_disasm.c index 3ef3093560ba..bfed711258ce 100644 --- a/tools/bpf/bpftool/jit_disasm.c +++ b/tools/bpf/bpftool/jit_disasm.c @@ -11,6 +11,8 @@ * Licensed under the GNU General Public License, version 2.0 (GPLv2) */ +#define _GNU_SOURCE +#include #include #include #include @@ -44,11 +46,13 @@ static int fprintf_json(void *out, const char *fmt, ...) char *s; va_start(ap, fmt); + if (vasprintf(&s, fmt, ap) < 0) + return -1; + va_end(ap); + if (!oper_count) { int i; - s = va_arg(ap, char *); - /* Strip trailing spaces */ i = strlen(s) - 1; while (s[i] == ' ') @@ -61,11 +65,10 @@ static int fprintf_json(void *out, const char *fmt, ...) } else if (!strcmp(fmt, ",")) { /* Skip */ } else { - s = va_arg(ap, char *); jsonw_string(json_wtr, s); oper_count++; } - va_end(ap); + free(s); return 0; } -- 2.20.1