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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 C0059C7618F for ; Mon, 15 Jul 2019 14:01:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9915520C01 for ; Mon, 15 Jul 2019 14:01:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563199310; bh=tKvy5JbcZXx6YWzfQrPDW5p7WMo9r0DbLOyr2sIo3UE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sDOULaQhJjTAhGgQ6REUDCv4P/afOBrAktuvDAx3y9fgj42okeYr8X5wy7v/gJNFk zwoSYMZltT2DXU47j/Anid3azw73JD4919Vm3xInnz12RRjfvy/NzwAx0lP0uPniQr so2/HGl6663pEiVo/KrNcCSAEb1S7Q+9xI3vCjUM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733241AbfGOOBt (ORCPT ); Mon, 15 Jul 2019 10:01:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:44588 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730529AbfGOOBs (ORCPT ); Mon, 15 Jul 2019 10:01:48 -0400 Received: from sasha-vm.mshome.net (unknown [73.61.17.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9E92B21841; Mon, 15 Jul 2019 14:01:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563199306; bh=tKvy5JbcZXx6YWzfQrPDW5p7WMo9r0DbLOyr2sIo3UE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qS/UsNgbiUvw8DxlbOHoaSs44aAp4RnqQ+A4/Mu3ifpt012+3cs5VI6eFfG6iFbUC mQGjke9mW7up1eqCCSGLCpWeuw3NYxP0LKoYKrzGBwH1pJVgOH5/1iv/ah018m+yOz J9xMK4J9tBNn/bCn1VgRZWOXhpNi2oHYUvxHEN6g= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jiri Olsa , Michael Petlan , Jiri Olsa , Quentin Monnet , Jakub Kicinski , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 231/249] tools: bpftool: Fix json dump crash on powerpc Date: Mon, 15 Jul 2019 09:46:36 -0400 Message-Id: <20190715134655.4076-231-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190715134655.4076-1-sashal@kernel.org> References: <20190715134655.4076-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jiri Olsa [ 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