From patchwork Mon Jun 29 19:57:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 11632025 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2D5F614E3 for ; Mon, 29 Jun 2020 20:01:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E06C206F1 for ; Mon, 29 Jun 2020 20:01:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388376AbgF2UBh (ORCPT ); Mon, 29 Jun 2020 16:01:37 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:37270 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388122AbgF2UBg (ORCPT ); Mon, 29 Jun 2020 16:01:36 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out03.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jpzyB-0005Vb-G4; Mon, 29 Jun 2020 14:01:35 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1jpzyA-0007zH-8m; Mon, 29 Jun 2020 14:01:35 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Cc: David Miller , Greg Kroah-Hartman , Tetsuo Handa , Alexei Starovoitov , Kees Cook , Andrew Morton , Alexei Starovoitov , Al Viro , bpf , linux-fsdevel , Daniel Borkmann , Jakub Kicinski , Masahiro Yamada , Gary Lin , Bruno Meneguele , LSM List , Casey Schaufler , Luis Chamberlain , Linus Torvalds References: <20200625095725.GA3303921@kroah.com> <778297d2-512a-8361-cf05-42d9379e6977@i-love.sakura.ne.jp> <20200625120725.GA3493334@kroah.com> <20200625.123437.2219826613137938086.davem@davemloft.net> <87pn9mgfc2.fsf_-_@x220.int.ebiederm.org> <87y2oac50p.fsf@x220.int.ebiederm.org> <87bll17ili.fsf_-_@x220.int.ebiederm.org> Date: Mon, 29 Jun 2020 14:57:03 -0500 In-Reply-To: <87bll17ili.fsf_-_@x220.int.ebiederm.org> (Eric W. Biederman's message of "Mon, 29 Jun 2020 14:55:05 -0500") Message-ID: <87zh8l63xs.fsf_-_@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 X-XM-SPF: eid=1jpzyA-0007zH-8m;;;mid=<87zh8l63xs.fsf_-_@x220.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18tkilkwueNF9nWNOIZyHygLGlNpkZV+hs= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on sa07.xmission.com X-Spam-Level: X-Spam-Status: No, score=0.5 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TM2_M_HEADER_IN_MSG,T_TooManySym_01,XMSubLong autolearn=disabled version=3.4.2 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 0; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: ; sa07 0; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ; X-Spam-Relay-Country: X-Spam-Timing: total 788 ms - load_scoreonly_sql: 0.04 (0.0%), signal_user_changed: 10 (1.3%), b_tie_ro: 9 (1.2%), parse: 0.95 (0.1%), extract_message_metadata: 18 (2.3%), get_uri_detail_list: 1.56 (0.2%), tests_pri_-1000: 91 (11.6%), tests_pri_-950: 2.1 (0.3%), tests_pri_-900: 1.79 (0.2%), tests_pri_-90: 290 (36.8%), check_bayes: 286 (36.4%), b_tokenize: 36 (4.5%), b_tok_get_all: 22 (2.8%), b_comp_prob: 2.7 (0.3%), b_tok_touch_all: 221 (28.0%), b_finish: 1.00 (0.1%), tests_pri_0: 337 (42.8%), check_dkim_signature: 0.75 (0.1%), check_dkim_adsp: 2.5 (0.3%), poll_dns_idle: 0.27 (0.0%), tests_pri_10: 3.7 (0.5%), tests_pri_500: 13 (1.6%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH v2 02/15] umh: Move setting PF_UMH into umh_pipe_setup X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: I am separating the code specific to user mode drivers from the code for ordinary user space helpers. Move setting of PF_UMH from call_usermodehelper_exec_async which is core user mode helper code into umh_pipe_setup which is user mode driver code. The code is equally as easy to write in one location as the other and the movement minimizes the impact of the user mode driver code on the core of the user mode helper code. Setting PF_UMH unconditionally is harmless as an action will only happen if it is paired with an entry on umh_list. Link: https://lkml.kernel.org/r/87bll6gf8t.fsf_-_@x220.int.ebiederm.org Reviewed-by: Greg Kroah-Hartman Signed-off-by: "Eric W. Biederman" --- kernel/umh.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/kernel/umh.c b/kernel/umh.c index c2a582b3a2bf..e6b9d6636850 100644 --- a/kernel/umh.c +++ b/kernel/umh.c @@ -102,12 +102,10 @@ static int call_usermodehelper_exec_async(void *data) commit_creds(new); - if (sub_info->file) { + if (sub_info->file) retval = do_execve_file(sub_info->file, sub_info->argv, sub_info->envp); - if (!retval) - current->flags |= PF_UMH; - } else + else retval = do_execve(getname_kernel(sub_info->path), (const char __user *const __user *)sub_info->argv, (const char __user *const __user *)sub_info->envp); @@ -468,6 +466,7 @@ static int umh_pipe_setup(struct subprocess_info *info, struct cred *new) umh_info->pipe_to_umh = to_umh[1]; umh_info->pipe_from_umh = from_umh[0]; umh_info->pid = task_pid_nr(current); + current->flags |= PF_UMH; return 0; }