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=-16.5 required=3.0 tests=DATE_IN_PAST_12_24, DKIMWL_WL_MED,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham 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 44B92C0044D for ; Sun, 15 Mar 2020 02:14:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1478920637 for ; Sun, 15 Mar 2020 02:14:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="N7nblpYK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727749AbgCOCOm (ORCPT ); Sat, 14 Mar 2020 22:14:42 -0400 Received: from mail-oi1-f201.google.com ([209.85.167.201]:51342 "EHLO mail-oi1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726655AbgCOCOl (ORCPT ); Sat, 14 Mar 2020 22:14:41 -0400 Received: by mail-oi1-f201.google.com with SMTP id 16so8333389oii.18 for ; Sat, 14 Mar 2020 19:14:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=OdlDyP22xWR3iukZ6BIAXqjFyoG87PPBI1OEHmhmYzg=; b=N7nblpYKFSWiHR4C7o2uBIQ0yrDCqVY7JzbxwILu5MSzDlQpa176KvICe4UFvqGjTp 4zjA8Z4OD7fsI1cEHxVpAxllS6ZaQH7E1o4jaD+IqnnJw7M9PY0uhX4jYOheFA1HuWJ7 lByKB7zbxlmsY06LfbHpK0PertOtJfngT6JPW+w3+a04kHdfKO9oHyaEEGZ3NSPT9gSg 2Ir7OZG51xSn5q8DXQYirEr+MGNdX5GZ2wEC/vWm4aZs5Ur/qv2Gt5XPTk9EGBksPtvf mRjj212EJMKNa/ImfBSyZw7OHAjiU70EJ8fZB7dbFsTnnuhU1qfNuvXnc2I6Zcx8ANLE E4kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=OdlDyP22xWR3iukZ6BIAXqjFyoG87PPBI1OEHmhmYzg=; b=rVBYaRnSkQjl1K1v/EJELh4sxFKguUBSg722MamYsEmErp2fvU+VQFm41eFtwWhFO6 7Irb95wTIfYOQOLEYopHFX8lgAxDk/wvN8Bfga8HBQhYDIgXC+7gDJkNNnrTAv3zcTYR eXR8rIjNy1AVwEIiOEEr85hnUzpkfPrF/e0F/AZ9MnAESxVyAwAqUwbv5U8uLFn1Zaht Ft1HwzA87a1QKiHHXS8Si6eiI5M9cPBhAh0dYeFLYTkPfHUo6QlUhbKe2nc+UrzRoLgg 9ozPUfWTkb2BnZ9YV8YJhBKbDgCfF+FkkdGyn7hniNytzjDRdg1XWq5MiETt7Uyf1xlI bqpg== X-Gm-Message-State: ANhLgQ2fK3vb071kAHB5dUHCF+OA6u5q4BIU7ZzOAED4N9H+/YZU/krm hOqn4p8NJSdmv1jCDHdeBgvVBxmVrGqv X-Google-Smtp-Source: ADFU+vuvgvEpt/9FO1yYRPr4PH2UMVclGaCFAYMBofq2DdoRP87MR/9gc9z+N1Zb0WJnwZSK8HqIWz+D+y0j X-Received: by 2002:a17:90a:e38a:: with SMTP id b10mr5576509pjz.159.1584160110864; Fri, 13 Mar 2020 21:28:30 -0700 (PDT) Date: Fri, 13 Mar 2020 21:28:26 -0700 Message-Id: <20200314042826.166953-1-irogers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.25.1.481.gfbce0eb801-goog Subject: [PATCH] perf mem2node: avoid double free related to realloc From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Cc: Stephane Eranian , Ian Rogers Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Realloc of size zero is a free not an error, avoid this causing a double free. Caught by clang's address sanitizer: ==2634==ERROR: AddressSanitizer: attempting double-free on 0x6020000015f0 in thread T0: #0 0x5649659297fd in free llvm/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:123:3 #1 0x5649659e9251 in __zfree tools/lib/zalloc.c:13:2 #2 0x564965c0f92c in mem2node__exit tools/perf/util/mem2node.c:114:2 #3 0x564965a08b4c in perf_c2c__report tools/perf/builtin-c2c.c:2867:2 #4 0x564965a0616a in cmd_c2c tools/perf/builtin-c2c.c:2989:10 #5 0x564965944348 in run_builtin tools/perf/perf.c:312:11 #6 0x564965943235 in handle_internal_command tools/perf/perf.c:364:8 #7 0x5649659440c4 in run_argv tools/perf/perf.c:408:2 #8 0x564965942e41 in main tools/perf/perf.c:538:3 0x6020000015f0 is located 0 bytes inside of 1-byte region [0x6020000015f0,0x6020000015f1) freed by thread T0 here: #0 0x564965929da3 in realloc third_party/llvm/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0x564965c0f55e in mem2node__init tools/perf/util/mem2node.c:97:16 #2 0x564965a08956 in perf_c2c__report tools/perf/builtin-c2c.c:2803:8 #3 0x564965a0616a in cmd_c2c tools/perf/builtin-c2c.c:2989:10 #4 0x564965944348 in run_builtin tools/perf/perf.c:312:11 #5 0x564965943235 in handle_internal_command tools/perf/perf.c:364:8 #6 0x5649659440c4 in run_argv tools/perf/perf.c:408:2 #7 0x564965942e41 in main tools/perf/perf.c:538:3 previously allocated by thread T0 here: #0 0x564965929c42 in calloc third_party/llvm/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0x5649659e9220 in zalloc tools/lib/zalloc.c:8:9 #2 0x564965c0f32d in mem2node__init tools/perf/util/mem2node.c:61:12 #3 0x564965a08956 in perf_c2c__report tools/perf/builtin-c2c.c:2803:8 #4 0x564965a0616a in cmd_c2c tools/perf/builtin-c2c.c:2989:10 #5 0x564965944348 in run_builtin tools/perf/perf.c:312:11 #6 0x564965943235 in handle_internal_command tools/perf/perf.c:364:8 #7 0x5649659440c4 in run_argv tools/perf/perf.c:408:2 #8 0x564965942e41 in main tools/perf/perf.c:538:3 Signed-off-by: Ian Rogers --- tools/perf/util/mem2node.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/mem2node.c b/tools/perf/util/mem2node.c index 797d86a1ab09..7f97aa69eb65 100644 --- a/tools/perf/util/mem2node.c +++ b/tools/perf/util/mem2node.c @@ -95,7 +95,7 @@ int mem2node__init(struct mem2node *map, struct perf_env *env) /* Cut unused entries, due to merging. */ tmp_entries = realloc(entries, sizeof(*entries) * j); - if (tmp_entries) + if (j == 0 || tmp_entries) entries = tmp_entries; for (i = 0; i < j; i++) { -- 2.25.1.481.gfbce0eb801-goog