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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D9B0C38159 for ; Fri, 20 Jan 2023 18:58:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229458AbjATS6m (ORCPT ); Fri, 20 Jan 2023 13:58:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229604AbjATS6l (ORCPT ); Fri, 20 Jan 2023 13:58:41 -0500 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC518743B7 for ; Fri, 20 Jan 2023 10:58:39 -0800 (PST) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5028c723d28so9695507b3.15 for ; Fri, 20 Jan 2023 10:58:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:mime-version:message-id:date:from:to:cc:subject :date:message-id:reply-to; bh=68orcaC6zz4yh42URgC/a9ocEH5eMY9g7tAnmpuRu0U=; b=WNTK3yTY8uIAwslAVYOxaLgjPBSTBNADsLlJcs4wVM2i+mwdBi98fG+N9/9iPIS0yc LJKYipiY96DE871/jJLOP3SwwmvmFPqp84J33MN2EAZ2qeN5YfjPCXEi0gULzYbSNTY6 /4ORT31UDpsWZRnmMmw7Wfzmv2BH/cokhri/PMFTqukUo5fIH14Kof+5ijzON08bA9b6 fA6z2ycBL+DUd8C+Ik8O5Pk2AOda7/XOQOSs4XUn4LISrg8FbEm3KIU+wyHPvgr69tE2 cz1zFUYSB8UJkHgr4t78a9r/DSw3tqQvC5q0My+SN8T+3IfpHpcJ7qiXgIpzlURBul2p p1OA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:mime-version:message-id:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=68orcaC6zz4yh42URgC/a9ocEH5eMY9g7tAnmpuRu0U=; b=k1XhGjv2wSi8s7pzy69fPKQ+GZX3/FazBKwmqv9dOTBPkoMRjNmPmr6wz02/BjuC8n +yRaDPmc6sqe94HsXEwDOF1qIQevE5zOQzX047nXYy3S3qEzRf0SgKJ31fiAX2xtwNa2 FXrZZQ4slbQpBW/CgDYniO0YXfBS4JHiKKNm/NT4Ub8cnwcTLcFvaLDn+20sjbUb0ZYs 33wbk8+khCa5CDtORHLH1j9sceIg5y0MxOxgSGM8OQICGgkPFEjSA2+OMtXA+m5VGAYq M76utwHpjW/x/X8DlSdeLnqjQE9hp0145AIBAwWuHO7zhG62rDTdWl26vz/M6E5S8XKr 2Ujg== X-Gm-Message-State: AFqh2koY2tHdiV2bc3OFeMBRnWTNe8mQGVP4wYKU2Sk2t0F5TtZ8vIHU p1JvG1ETv6p2ngiiAZmV0HyszRNINpWl X-Google-Smtp-Source: AMrXdXuR0UGEvg0tmZsuCJFjqwMeNjP70VdhJX4rPI/yED1obovEegVXuTIVRHcRLI9m8lPABvuYksRokxPA X-Received: from irogers.svl.corp.google.com ([2620:15c:2d4:203:a736:5d8d:4ad8:4e50]) (user=irogers job=sendgmr) by 2002:a05:690c:887:b0:500:ac2c:80fb with SMTP id cd7-20020a05690c088700b00500ac2c80fbmr278306ywb.90.1674241119207; Fri, 20 Jan 2023 10:58:39 -0800 (PST) Date: Fri, 20 Jan 2023 10:58:28 -0800 Message-Id: <20230120185828.43231-1-irogers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.39.0.246.g2a6d74b583-goog Subject: [PATCH v2] perf buildid: Avoid copy of uninitialized memory From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Nathan Chancellor , Nick Desaulniers , Tom Rix , Ian Rogers , Adrian Hunter , Leo Yan , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Cc: Stephane Eranian , Arnaldo Carvalho de Melo Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org build_id__init only copies the buildid data up to size leaving the rest of the data array uninitialized. Copying the full array during synthesis means the written event contains uninitialized memory. Ensure the size is less that the buffer size and only copy the bytes that were initialized. This was detected by the Clang/LLVM memory sanitizer. Suggested-by: Arnaldo Carvalho de Melo Signed-off-by: Ian Rogers v2. Avoids the potential for copying too much as suggested by Arnaldo. --- tools/perf/util/synthetic-events.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c index 3ab6a92b1a6d..9ab9308ee80c 100644 --- a/tools/perf/util/synthetic-events.c +++ b/tools/perf/util/synthetic-events.c @@ -2219,8 +2219,8 @@ int perf_event__synthesize_build_id(struct perf_tool *tool, struct dso *pos, u16 len = pos->long_name_len + 1; len = PERF_ALIGN(len, NAME_ALIGN); - memcpy(&ev.build_id.build_id, pos->bid.data, sizeof(pos->bid.data)); - ev.build_id.size = pos->bid.size; + ev.build_id.size = min(pos->bid.size, sizeof(pos->bid.data)); + memcpy(&ev.build_id.build_id, pos->bid.data, ev.build_id.size); ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID; ev.build_id.header.misc = misc | PERF_RECORD_MISC_BUILD_ID_SIZE; ev.build_id.pid = machine->pid; -- 2.39.0.246.g2a6d74b583-goog