From patchwork Sat May 9 19:41:17 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: 11538503 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 7CA4B14B4 for ; Sat, 9 May 2020 19:44:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6365A208DB for ; Sat, 9 May 2020 19:44:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728500AbgEITos (ORCPT ); Sat, 9 May 2020 15:44:48 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:53504 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727938AbgEITor (ORCPT ); Sat, 9 May 2020 15:44:47 -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 1jXVOw-0000nF-GS; Sat, 09 May 2020 13:44:46 -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 1jXVOv-0006Yo-Mw; Sat, 09 May 2020 13:44:46 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Cc: Linus Torvalds , Oleg Nesterov , Jann Horn , Kees Cook , Greg Ungerer , Rob Landley , Bernd Edlinger , , Al Viro , Alexey Dobriyan , Andrew Morton , Casey Schaufler , linux-security-module@vger.kernel.org, James Morris , "Serge E. Hallyn" , Andy Lutomirski References: <87h7wujhmz.fsf@x220.int.ebiederm.org> <87sgga6ze4.fsf@x220.int.ebiederm.org> <87v9l4zyla.fsf_-_@x220.int.ebiederm.org> Date: Sat, 09 May 2020 14:41:17 -0500 In-Reply-To: <87v9l4zyla.fsf_-_@x220.int.ebiederm.org> (Eric W. Biederman's message of "Sat, 09 May 2020 14:40:17 -0500") Message-ID: <87k11kzyjm.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=1jXVOv-0006Yo-Mw;;;mid=<87k11kzyjm.fsf_-_@x220.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+AGw81UWuOF7eURcXUoWmPIIkBUcFGjcs= 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 sa08.xmission.com X-Spam-Level: ** X-Spam-Status: No, score=2.5 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TooManySym_01,XMGappySubj_01,XMNoVowels,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] * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.5 XMGappySubj_01 Very gappy subject * 0.7 XMSubLong Long Subject * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa08 0; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: ; sa08 0; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **; X-Spam-Relay-Country: X-Spam-Timing: total 453 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 14 (3.2%), b_tie_ro: 12 (2.7%), parse: 1.13 (0.2%), extract_message_metadata: 12 (2.7%), get_uri_detail_list: 2.4 (0.5%), tests_pri_-1000: 13 (2.8%), tests_pri_-950: 1.37 (0.3%), tests_pri_-900: 1.11 (0.2%), tests_pri_-90: 96 (21.3%), check_bayes: 95 (20.9%), b_tokenize: 9 (2.0%), b_tok_get_all: 10 (2.1%), b_comp_prob: 3.0 (0.7%), b_tok_touch_all: 68 (15.1%), b_finish: 1.22 (0.3%), tests_pri_0: 300 (66.1%), check_dkim_signature: 0.51 (0.1%), check_dkim_adsp: 2.7 (0.6%), poll_dns_idle: 1.09 (0.2%), tests_pri_10: 3.5 (0.8%), tests_pri_500: 8 (1.7%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH 2/5] exec: Directly call security_bprm_set_creds from __do_execve_file 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: Now that security_bprm_set_creds is no longer responsible for calling cap_bprm_set_creds, security_bprm_set_creds only does something for the primary file that is being executed (not any interpreters it may have). Therefore call security_bprm_set_creds from __do_execve_file, instead of from prepare_binprm so that it is only called once, and remove the now unnecessary called_set_creds field of struct binprm. Signed-off-by: "Eric W. Biederman" --- fs/exec.c | 11 +++++------ include/linux/binfmts.h | 6 ------ security/apparmor/domain.c | 3 --- security/selinux/hooks.c | 2 -- security/smack/smack_lsm.c | 3 --- security/tomoyo/tomoyo.c | 6 ------ 6 files changed, 5 insertions(+), 26 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 765bfd51a546..635b5085050c 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1635,12 +1635,6 @@ int prepare_binprm(struct linux_binprm *bprm) bprm_fill_uid(bprm); - /* fill in binprm security blob */ - retval = security_bprm_set_creds(bprm); - if (retval) - return retval; - bprm->called_set_creds = 1; - retval = cap_bprm_set_creds(bprm); if (retval) return retval; @@ -1858,6 +1852,11 @@ static int __do_execve_file(int fd, struct filename *filename, if (retval < 0) goto out; + /* fill in binprm security blob */ + retval = security_bprm_set_creds(bprm); + if (retval) + goto out; + retval = prepare_binprm(bprm); if (retval < 0) goto out; diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 1b48e2154766..42f760acfc2c 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -26,12 +26,6 @@ struct linux_binprm { unsigned long p; /* current top of mem */ unsigned long argmin; /* rlimit marker for copy_strings() */ unsigned int - /* - * True after the bprm_set_creds hook has been called once - * (multiple calls can be made via prepare_binprm() for - * binfmt_script/misc). - */ - called_set_creds:1, /* * True if most recent call to the commoncaps bprm_set_creds * hook (due to multiple prepare_binprm() calls from the diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index 6ceb74e0f789..61b9181a9e1f 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -875,9 +875,6 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) file_inode(bprm->file)->i_mode }; - if (bprm->called_set_creds) - return 0; - ctx = task_ctx(current); AA_BUG(!cred_label(bprm->cred)); AA_BUG(!ctx); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 0b4e32161b77..ff3e1be53da5 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2297,8 +2297,6 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm) /* SELinux context only depends on initial program or script and not * the script interpreter */ - if (bprm->called_set_creds) - return 0; old_tsec = selinux_cred(current_cred()); new_tsec = selinux_cred(bprm->cred); diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 8c61d175e195..bd1967730fec 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -904,9 +904,6 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm) struct superblock_smack *sbsp; int rc; - if (bprm->called_set_creds) - return 0; - isp = smack_inode(inode); if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) return 0; diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c index 716c92ec941a..d965ce80a7fb 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -71,12 +71,6 @@ static void tomoyo_bprm_committed_creds(struct linux_binprm *bprm) */ static int tomoyo_bprm_set_creds(struct linux_binprm *bprm) { - /* - * Do only if this function is called for the first time of an execve - * operation. - */ - if (bprm->called_set_creds) - return 0; /* * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested * for the first time.