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=-16.6 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_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 93685C43381 for ; Mon, 18 Feb 2019 22:07:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5AF6321479 for ; Mon, 18 Feb 2019 22:07:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="oCyOYBPN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731447AbfBRWHd (ORCPT ); Mon, 18 Feb 2019 17:07:33 -0500 Received: from mail-yb1-f202.google.com ([209.85.219.202]:38648 "EHLO mail-yb1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729530AbfBRWHd (ORCPT ); Mon, 18 Feb 2019 17:07:33 -0500 Received: by mail-yb1-f202.google.com with SMTP id 69so9620236ybf.5 for ; Mon, 18 Feb 2019 14:07:33 -0800 (PST) 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=uyrjSL12XYcAJ7X16b+lcNVmEe0yoTnAu2FCRMKgvOY=; b=oCyOYBPNAQ/y50GYzlEq92tvgttp46mIb6X4hWkZMRrJZwfa9+aaPhVtjBGZ+UshAn uOaKOGEb86VZIO9eoqnHmN5GdRMnW9PVP8iV7dfjlQSoHs0JUZ6xE7v0+CEACcrQ1/AK 2DkarS3nkjX9/yi/64oguVlPgL6uKvAQ/24J8HjHYP9HIXBSPuMB82e1+GMofkVt/YUJ crkhTWRC4QleyW2Pl3EkJdKSwkqdkmDeurAnYfSPsbLa1Pa386/QY9aZGuS8QGeIy1Ax TdE/sIkRZof3PHqDKwCN4znVVW9IVB+EOtuI1RSI2hL9fOmFSuKKEkDKwOHsJhGy8xxy z9vA== 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=uyrjSL12XYcAJ7X16b+lcNVmEe0yoTnAu2FCRMKgvOY=; b=BPykV32U+/h2iyfhuUMuk+yk3FVKjIYezI5lCXYjQUgdObxiVd8ZGJNaMLgIB1oEDT ibNDOio/Ufd2IGoFSqAEvArdo9/npJ23RuNKGGyVu85L7xV+aRned4mnqy+hYbnA56lT pWHp3bkbjiLowHy0CG2td3ZRHXwJKhEbRl4g8Fu/eZJQCt2p02i9c4QefqAiSK/M53td pezpsoZhzy6xfPCHsHVrfBKog8eg8TkoeJ1or1gqEv4Y5q1Z8rBdtF/OsRgZ7Y3Eahmt akFOlZMvoIpvzRdApg13hprnBDF9uNh4cHhU/nZyN8HFgqZs1fulQCsTzXS9RnopP189 c0Qw== X-Gm-Message-State: AHQUAuY1vqPMkh9RtrFq4ZqChiRT4o13CkjZVJamg+0t8Knt6jzlsvun ORVZK2YRSk778fqofxf0cXIs6AXY9g== X-Google-Smtp-Source: AHgI3IYISTPyZVE1YaUvvnYT8JzsNYCnJX6rE3bGDjoc6CyIj2tRodjW+zM3fbrbZHHPgl9MyIBGmHI9Iw== X-Received: by 2002:a81:6c48:: with SMTP id h69mr3505905ywc.17.1550527652619; Mon, 18 Feb 2019 14:07:32 -0800 (PST) Date: Mon, 18 Feb 2019 23:07:23 +0100 Message-Id: <20190218220723.176737-1-jannh@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.21.0.rc0.258.g878e2cd30e-goog Subject: [PATCH] perf/core: use strndup_user() instead of buggy open-coded version From: Jann Horn To: Ingo Molnar , Steven Rostedt , jannh@google.com Cc: linux-kernel@vger.kernel.org, Song Liu , Masami Hiramatsu 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 The first version of this method was missing the check for `ret == PATH_MAX`; then such a check was added, but it didn't call kfree() on error, so there was still a small memory leak in the error case. Fix it by using strndup_user() instead of open-coding it. Fixes: 0eadcc7a7bc0 ("perf/core: Fix perf_uprobe_init()") Signed-off-by: Jann Horn --- compile-tested only kernel/trace/trace_event_perf.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 76217bbef815..c744b02081c3 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -299,15 +299,11 @@ int perf_uprobe_init(struct perf_event *p_event, if (!p_event->attr.uprobe_path) return -EINVAL; - path = kzalloc(PATH_MAX, GFP_KERNEL); - if (!path) - return -ENOMEM; - ret = strncpy_from_user( - path, u64_to_user_ptr(p_event->attr.uprobe_path), PATH_MAX); - if (ret == PATH_MAX) - return -E2BIG; - if (ret < 0) - goto out; + + path = strndup_user(u64_to_user_ptr(p_event->attr.uprobe_path), + PATH_MAX); + if (IS_ERR(path)) + return PTR_ERR(path); if (path[0] == '\0') { ret = -EINVAL; goto out; -- 2.21.0.rc0.258.g878e2cd30e-goog