From patchwork Thu Jul 2 16:41:25 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: 11639723 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 1B24D13B6 for ; Thu, 2 Jul 2020 16:47:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CF5720885 for ; Thu, 2 Jul 2020 16:47:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726671AbgGBQr2 (ORCPT ); Thu, 2 Jul 2020 12:47:28 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:34832 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726300AbgGBQr1 (ORCPT ); Thu, 2 Jul 2020 12:47:27 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out02.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jr2Mw-0007X4-4k; Thu, 02 Jul 2020 10:47:26 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.int.ebiederm.org) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1jr2Mv-0007up-0i; Thu, 02 Jul 2020 10:47:25 -0600 From: "Eric W. Biederman" To: linux-kernel@vger.kernel.org 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 , Christian Brauner , "Eric W. Biederman" , Greg Kroah-Hartman Date: Thu, 2 Jul 2020 11:41:25 -0500 Message-Id: <20200702164140.4468-1-ebiederm@xmission.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <87y2o1swee.fsf_-_@x220.int.ebiederm.org> References: <87y2o1swee.fsf_-_@x220.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1jr2Mv-0007up-0i;;;mid=<20200702164140.4468-1-ebiederm@xmission.com>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+9a2nEzb5kxzsVEIPl/pzWXpFWlTcB7SA= 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 sa06.xmission.com X-Spam-Level: X-Spam-Status: No, score=-0.2 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TM2_M_HEADER_IN_MSG,T_TooManySym_01 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] * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa06 0; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: ; sa06 0; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;linux-kernel@vger.kernel.org X-Spam-Relay-Country: X-Spam-Timing: total 580 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 12 (2.0%), b_tie_ro: 10 (1.8%), parse: 1.61 (0.3%), extract_message_metadata: 24 (4.2%), get_uri_detail_list: 4.0 (0.7%), tests_pri_-1000: 25 (4.2%), tests_pri_-950: 1.97 (0.3%), tests_pri_-900: 1.64 (0.3%), tests_pri_-90: 251 (43.2%), check_bayes: 236 (40.7%), b_tokenize: 24 (4.2%), b_tok_get_all: 8 (1.3%), b_comp_prob: 4.0 (0.7%), b_tok_touch_all: 196 (33.7%), b_finish: 0.95 (0.2%), tests_pri_0: 249 (42.9%), check_dkim_signature: 0.56 (0.1%), check_dkim_adsp: 2.0 (0.3%), poll_dns_idle: 0.37 (0.1%), tests_pri_10: 2.2 (0.4%), tests_pri_500: 7 (1.2%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH v3 01/16] umh: Capture the pid in 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: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The pid in struct subprocess_info is only used by umh_clean_and_save_pid to write the pid into umh_info. Instead always capture the pid on struct umh_info in umh_pipe_setup, removing code that is specific to user mode drivers from the common user path of user mode helpers. v1: https://lkml.kernel.org/r/87h7uygf9i.fsf_-_@x220.int.ebiederm.org v2: https://lkml.kernel.org/r/875zb97iix.fsf_-_@x220.int.ebiederm.org Reviewed-by: Greg Kroah-Hartman Signed-off-by: "Eric W. Biederman" --- include/linux/umh.h | 1 - kernel/umh.c | 5 ++--- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/include/linux/umh.h b/include/linux/umh.h index 0c08de356d0d..aae16a0ebd0f 100644 --- a/include/linux/umh.h +++ b/include/linux/umh.h @@ -25,7 +25,6 @@ struct subprocess_info { struct file *file; int wait; int retval; - pid_t pid; int (*init)(struct subprocess_info *info, struct cred *new); void (*cleanup)(struct subprocess_info *info); void *data; diff --git a/kernel/umh.c b/kernel/umh.c index 79f139a7ca03..c2a582b3a2bf 100644 --- a/kernel/umh.c +++ b/kernel/umh.c @@ -102,7 +102,6 @@ static int call_usermodehelper_exec_async(void *data) commit_creds(new); - sub_info->pid = task_pid_nr(current); if (sub_info->file) { retval = do_execve_file(sub_info->file, sub_info->argv, sub_info->envp); @@ -468,6 +467,7 @@ 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); return 0; } @@ -476,13 +476,12 @@ static void umh_clean_and_save_pid(struct subprocess_info *info) struct umh_info *umh_info = info->data; /* cleanup if umh_pipe_setup() was successful but exec failed */ - if (info->pid && info->retval) { + if (info->retval) { fput(umh_info->pipe_to_umh); fput(umh_info->pipe_from_umh); } argv_free(info->argv); - umh_info->pid = info->pid; } /**