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=-17.4 required=3.0 tests=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 21C99C4332B for ; Fri, 20 Mar 2020 18:23:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E186320784 for ; Fri, 20 Mar 2020 18:23:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CU06efIQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726843AbgCTSX5 (ORCPT ); Fri, 20 Mar 2020 14:23:57 -0400 Received: from mail-pf1-f202.google.com ([209.85.210.202]:48027 "EHLO mail-pf1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725446AbgCTSX5 (ORCPT ); Fri, 20 Mar 2020 14:23:57 -0400 Received: by mail-pf1-f202.google.com with SMTP id h191so5133016pfe.14 for ; Fri, 20 Mar 2020 11:23:54 -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=RMPXYe/vR5ct6qGO4irRpO9ggqjWQLrULMnyekYeYdA=; b=CU06efIQZInxH335XVehXng0U+lS//aZfnaXxvf0I2ImUfFSVaakHLgoP/P2TI4ezk X1bS7ff5J9PuTwD3G3siGmY6So6qmAl7PFskKQTCgPd25wnt769kl8x9l2Apf9BkotnG ShNZxWCskCFjJSirTG4wL/8STJVJPY5LoGahYYkbHz8+vyQrLWtwdGPIgXya4IhGGE8e KCHoyClSc1YOlYFWSOcepT1K/TGGchJFQwAvJrRMehnN4ShkdlSMdsAshg00Ra8p6yWd HWuZS1MnWkF+hmTHh23tcAkJ3fJZLMChDyG1EN1S3cXQLf4P9+j7vNXx4c8oDKRjD07u ucWw== 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=RMPXYe/vR5ct6qGO4irRpO9ggqjWQLrULMnyekYeYdA=; b=IHM5+2Yy7tZd+jKrwe6kgMbmfAyURCovf5Bzv8fJVN0k6XFlf/auhcPgrUfNXcY3On wDH3cQnzKrLnDqwlfG72cTtGLU00tqQXco1JLA73NePPpjdMPI1TP4MTEMn8Pn8Ovb0N 0knFuIjtaZr6UkPpUXlxuZdi1djmrypRwN6hVg7wL1Y28oSlKOtweV3h+CNqXYTI5mQq jPNtWUIZcOY8eT51nQYLbggkqmT94xOgrMMP00w6m0dv8vb2n40/CeMPXB4g3dTCZcQm JlHCus2m8GOssHbm+a4bO1GKPf4n1gMTIenDiF7lYIrYgZ3yl4MY5nM7Y3zZNTBqH45Y ecpg== X-Gm-Message-State: ANhLgQ1jh88TJcOtNl3LErC7QWoZ/tNkgHpnNgg1IWYGd7WW8zVpN8bm 5Q/JjH3s7HTo6Mbn8vgYjMgiWSQIh+EO X-Google-Smtp-Source: ADFU+vu7Ekr81cC6q+QtWqmhrDj4TMQcXjgygXB8DtY5pc1UlFHaNo/fQ80zM0Suh8w7hOCADMV5UkHFh4f1 X-Received: by 2002:a17:90a:8c83:: with SMTP id b3mr10818804pjo.1.1584728633692; Fri, 20 Mar 2020 11:23:53 -0700 (PDT) Date: Fri, 20 Mar 2020 11:23:47 -0700 Message-Id: <20200320182347.87675-1-irogers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.25.1.696.g5e7596f4ac-goog Subject: [PATCH v2] 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 v2: add a WARN_ON_ONCE when the free condition arises. Signed-off-by: Ian Rogers --- tools/perf/util/mem2node.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/mem2node.c b/tools/perf/util/mem2node.c index 797d86a1ab09..c84f5841c7ab 100644 --- a/tools/perf/util/mem2node.c +++ b/tools/perf/util/mem2node.c @@ -1,5 +1,6 @@ #include #include +#include #include #include #include @@ -95,7 +96,7 @@ 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 (tmp_entries || WARN_ON_ONCE(j == 0)) entries = tmp_entries; for (i = 0; i < j; i++) { -- 2.25.1.696.g5e7596f4ac-goog