From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755826Ab3GAURw (ORCPT ); Mon, 1 Jul 2013 16:17:52 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49070 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755467Ab3GAUKl (ORCPT ); Mon, 1 Jul 2013 16:10:41 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stephane Eranian , Jiri Olsa , Peter Zijlstra , Ingo Molnar Subject: [ 17/26] perf: Disable monitoring on setuid processes for regular users Date: Mon, 1 Jul 2013 13:10:12 -0700 Message-Id: <20130701200731.831672044@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130701200729.872850414@linuxfoundation.org> References: <20130701200729.872850414@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stephane Eranian commit 2976b10f05bd7f6dab9f9e7524451ddfed656a89 upstream. There was a a bug in setup_new_exec(), whereby the test to disabled perf monitoring was not correct because the new credentials for the process were not yet committed and therefore the get_dumpable() test was never firing. The patch fixes the problem by moving the perf_event test until after the credentials are committed. Signed-off-by: Stephane Eranian Tested-by: Jiri Olsa Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- fs/exec.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/fs/exec.c +++ b/fs/exec.c @@ -1136,13 +1136,6 @@ void setup_new_exec(struct linux_binprm set_dumpable(current->mm, suid_dumpable); } - /* - * Flush performance counters when crossing a - * security domain: - */ - if (!get_dumpable(current->mm)) - perf_event_exit_task(current); - /* An exec changes our domain. We are no longer part of the thread group */ @@ -1206,6 +1199,15 @@ void install_exec_creds(struct linux_bin commit_creds(bprm->cred); bprm->cred = NULL; + + /* + * Disable monitoring for regular users + * when executing setuid binaries. Must + * wait until new credentials are committed + * by commit_creds() above + */ + if (get_dumpable(current->mm) != SUID_DUMP_USER) + perf_event_exit_task(current); /* * cred_guard_mutex must be held at least to this point to prevent * ptrace_attach() from altering our determination of the task's