From patchwork Tue Jun 7 03:54:38 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 69464 Delivered-To: patch@linaro.org Received: by 10.140.106.246 with SMTP id e109csp1778834qgf; Mon, 6 Jun 2016 20:55:17 -0700 (PDT) X-Received: by 10.66.122.100 with SMTP id lr4mr27532626pab.99.1465271717058; Mon, 06 Jun 2016 20:55:17 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id d126si32403262pfd.10.2016.06.06.20.55.14; Mon, 06 Jun 2016 20:55:17 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753189AbcFGDzK (ORCPT + 31 others); Mon, 6 Jun 2016 23:55:10 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:44431 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751399AbcFGDzI (ORCPT ); Mon, 6 Jun 2016 23:55:08 -0400 Received: from 172.24.1.60 (EHLO szxeml426-hub.china.huawei.com) ([172.24.1.60]) by szxrg01-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id DLV70083; Tue, 07 Jun 2016 11:54:53 +0800 (CST) Received: from linux-4hy3.site (10.107.193.248) by szxeml426-hub.china.huawei.com (10.82.67.181) with Microsoft SMTP Server id 14.3.235.1; Tue, 7 Jun 2016 11:54:42 +0800 From: Wang Nan To: , CC: , , , Wang Nan , Arnaldo Carvalho de Melo Subject: [PATCH] perf tools: Fix crash in build_id_cache__kallsyms_path() Date: Tue, 7 Jun 2016 03:54:38 +0000 Message-ID: <1465271678-7392-1-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 MIME-Version: 1.0 X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020206.57564591.0040, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 532d07c66f157a0653204ee0fb0801b3 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org build_id_cache__kallsyms_path() accept string buffer but also alloc buffer by itself using asnprintf. Unfortunately, the only user of it passes it a stack-allocated buffer. Freeing it causes crash like this: $ perf script *** Error in `/home/wangnan/perf': free(): invalid pointer: 0x00007fffffff9630 *** ======= Backtrace: ========= lib64/libc.so.6(+0x6eeef)[0x7ffff5dbaeef] lib64/libc.so.6(+0x78cae)[0x7ffff5dc4cae] lib64/libc.so.6(+0x79987)[0x7ffff5dc5987] /home/w00229757/perf(build_id_cache__kallsyms_path+0x6b)[0x49681b] /home/w00229757/perf[0x4bdd40] /home/w00229757/perf(dso__load+0xa3a)[0x4c048a] /home/w00229757/perf(map__load+0x6f)[0x4d561f] /home/w00229757/perf(thread__find_addr_map+0x235)[0x49e935] /home/w00229757/perf(machine__resolve+0x7d)[0x49ec6d] /home/w00229757/perf[0x4555a8] /home/w00229757/perf[0x4d9507] /home/w00229757/perf[0x4d9e80] /home/w00229757/perf(ordered_events__flush+0x354)[0x4dd444] /home/w00229757/perf(perf_session__process_events+0x3d0)[0x4dc140] /home/w00229757/perf(cmd_script+0x12b0)[0x4592e0] /home/w00229757/perf[0x4911f1] /home/w00229757/perf(main+0x68f)[0x4352ef] /lib64/libc.so.6(__libc_start_main+0xf5)[0x7ffff5d6dbd5] /home/w00229757/perf[0x435415] ======= Memory map: ======== This patch simplify build_id_cache__kallsyms_path(), don't even consider allocate string buffer, so never free anything. The caller of it should management memory allocation. Signed-off-by: Wang Nan Cc: Masami Hiramatsu Cc: Arnaldo Carvalho de Melo Fixes: 01412261d994 ("perf buildid-cache: Use path/to/bin/buildid/elf instead of path/to/bin/buildid") --- tools/perf/util/build-id.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) -- 1.8.3.4 diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index 67f986c..20aef90 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -147,20 +147,17 @@ static int asnprintf(char **strp, size_t size, const char *fmt, ...) char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf, size_t size) { - bool is_alloc = !!bf; bool retry_old = true; - asnprintf(&bf, size, "%s/%s/%s/kallsyms", - buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); + snprintf(bf, size, "%s/%s/%s/kallsyms", + buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); retry: if (!access(bf, F_OK)) return bf; - if (is_alloc) - free(bf); if (retry_old) { /* Try old style kallsyms cache */ - asnprintf(&bf, size, "%s/%s/%s", - buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); + snprintf(bf, size, "%s/%s/%s", + buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); retry_old = false; goto retry; }