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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 9C53BC43381 for ; Tue, 5 Mar 2019 13:53:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FF202133F for ; Tue, 5 Mar 2019 13:53:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728582AbfCENxI (ORCPT ); Tue, 5 Mar 2019 08:53:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:37690 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728458AbfCENws (ORCPT ); Tue, 5 Mar 2019 08:52:48 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 241782146E; Tue, 5 Mar 2019 13:52:47 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.92-RC5) (envelope-from ) id 1h1AUw-00030G-9D; Tue, 05 Mar 2019 08:52:46 -0500 Message-Id: <20190305135246.180038284@goodmis.org> User-Agent: quilt/0.65 Date: Tue, 05 Mar 2019 08:52:26 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , stable@vger.kernel.org, Masami Hiramatsu , Song Liu , Jann Horn Subject: [for-next][PATCH 3/6] tracing/perf: Use strndup_user() instead of buggy open-coded version References: <20190305135223.360347148@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jann Horn 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. Link: http://lkml.kernel.org/r/20190220165443.152385-1-jannh@google.com Cc: Ingo Molnar Cc: stable@vger.kernel.org Fixes: 0eadcc7a7bc0 ("perf/core: Fix perf_uprobe_init()") Reviewed-by: Masami Hiramatsu Acked-by: Song Liu Signed-off-by: Jann Horn Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_event_perf.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 76217bbef815..4629a6104474 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -299,15 +299,13 @@ 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)) { + ret = PTR_ERR(path); + return (ret == -EINVAL) ? -E2BIG : ret; + } if (path[0] == '\0') { ret = -EINVAL; goto out; -- 2.20.1