From nobody Sun Sep 14 14:22:07 2025 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 E850DC05027 for ; Fri, 20 Jan 2023 18:58:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229915AbjATS6q (ORCPT ); Fri, 20 Jan 2023 13:58:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229746AbjATS6l (ORCPT ); Fri, 20 Jan 2023 13:58:41 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECD1E743BD for ; Fri, 20 Jan 2023 10:58:39 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id d21-20020a25add5000000b007ff8112e8b8so4781181ybe.17 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=T/iC234L0AVi6rUCcsuc6jjEiz1aHdzjGPsZNMhxp0ZkQVuKkPcf/mH6r7/vYI353g Z+VDYg049nOBPxevb7Aj09MCSnH0PQGWZWWsMH5FuGmkEsM8zhdf+2DfzMj/z+wEfssa PEfHXqkTVe3jwtP3U0Of7eqRgst/dln6bbv3j9n7158R0qb5D3dXF19x9Q32aRu6AzQz aDwiprdtg9ipYZYAgKi5fPkzwPBEJvydDYFUHhsVjkV0ailwAkXDiMOMqgw8tkQpRpwF waG6mCU+8qZtQmB9U5dvS4fAI2t3hhvuJMlq94ufe/kfC3nDVulGYKnsabycryh2DtUf Q2fg== X-Gm-Message-State: AFqh2krJO1I3bUlGM7GLaFUiQ1hkjwf8zkfV2AxsXVvv5pWKGFtzQuTj hKm2O5Sx2bzML2mCOXvRdnA2YMe6X9Wu 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 =20 len =3D pos->long_name_len + 1; len =3D PERF_ALIGN(len, NAME_ALIGN); - memcpy(&ev.build_id.build_id, pos->bid.data, sizeof(pos->bid.data)); - ev.build_id.size =3D pos->bid.size; + ev.build_id.size =3D 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 =3D PERF_RECORD_HEADER_BUILD_ID; ev.build_id.header.misc =3D misc | PERF_RECORD_MISC_BUILD_ID_SIZE; ev.build_id.pid =3D machine->pid; --=20 2.39.0.246.g2a6d74b583-goog