From patchwork Thu Feb 20 20:46:25 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: 11394999 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 DBAD392A for ; Thu, 20 Feb 2020 20:48:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA724208E4 for ; Thu, 20 Feb 2020 20:48:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729127AbgBTUsa (ORCPT ); Thu, 20 Feb 2020 15:48:30 -0500 Received: from out01.mta.xmission.com ([166.70.13.231]:59842 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728969AbgBTUsa (ORCPT ); Thu, 20 Feb 2020 15:48:30 -0500 Received: from in02.mta.xmission.com ([166.70.13.52]) by out01.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1j4skE-0001ri-62; Thu, 20 Feb 2020 13:48:26 -0700 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1j4skD-00085Y-Cz; Thu, 20 Feb 2020 13:48:26 -0700 From: ebiederm@xmission.com (Eric W. Biederman) To: Linus Torvalds Cc: Al Viro , LKML , Kernel Hardening , Linux API , Linux FS Devel , Linux Security Module , Akinobu Mita , Alexey Dobriyan , Andrew Morton , Andy Lutomirski , Daniel Micay , Djalal Harouni , "Dmitry V . Levin" , Greg Kroah-Hartman , Ingo Molnar , "J . Bruce Fields" , Jeff Layton , Jonathan Corbet , Kees Cook , Oleg Nesterov , Solar Designer References: <20200210150519.538333-8-gladkov.alexey@gmail.com> <87v9odlxbr.fsf@x220.int.ebiederm.org> <20200212144921.sykucj4mekcziicz@comp-core-i7-2640m-0182e6> <87tv3vkg1a.fsf@x220.int.ebiederm.org> <87v9obipk9.fsf@x220.int.ebiederm.org> <20200212200335.GO23230@ZenIV.linux.org.uk> <20200212203833.GQ23230@ZenIV.linux.org.uk> <20200212204124.GR23230@ZenIV.linux.org.uk> <87lfp7h422.fsf@x220.int.ebiederm.org> <87pnejf6fz.fsf@x220.int.ebiederm.org> Date: Thu, 20 Feb 2020 14:46:25 -0600 In-Reply-To: <87pnejf6fz.fsf@x220.int.ebiederm.org> (Eric W. Biederman's message of "Wed, 12 Feb 2020 22:37:52 -0600") Message-ID: <871rqpaswu.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=1j4skD-00085Y-Cz;;;mid=<871rqpaswu.fsf_-_@x220.int.ebiederm.org>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/Q6NKhmM+yXD+yJ+hS7KlJi2ul8+5zveY= 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=1.3 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TooManySym_01,XMNoVowels 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: 0.4907] * 1.5 XMNoVowels Alpha-numberic number with no vowels * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: *;Linus Torvalds X-Spam-Relay-Country: X-Spam-Timing: total 392 ms - load_scoreonly_sql: 0.03 (0.0%), signal_user_changed: 2.8 (0.7%), b_tie_ro: 1.97 (0.5%), parse: 1.00 (0.3%), extract_message_metadata: 3.0 (0.8%), get_uri_detail_list: 0.95 (0.2%), tests_pri_-1000: 4.4 (1.1%), tests_pri_-950: 1.37 (0.4%), tests_pri_-900: 1.07 (0.3%), tests_pri_-90: 28 (7.1%), check_bayes: 26 (6.7%), b_tokenize: 9 (2.2%), b_tok_get_all: 7 (1.9%), b_comp_prob: 2.5 (0.6%), b_tok_touch_all: 4.3 (1.1%), b_finish: 0.78 (0.2%), tests_pri_0: 334 (85.4%), check_dkim_signature: 0.50 (0.1%), check_dkim_adsp: 3.1 (0.8%), poll_dns_idle: 0.42 (0.1%), tests_pri_10: 1.97 (0.5%), tests_pri_500: 6 (1.5%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH 0/7] proc: Dentry flushing without proc_mnt 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 in02.mta.xmission.com) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Just because it is less of a fundamental change and less testing I went and looked at updating proc_flush_task to use a list as Al suggested. If we can stand an sget/deactivate_super pair for every dentry we want to invalidate I think I have something. Comments from anyone will be appreciated I gave this some light testing and the code is based on something similar already present in proc so I think there is a high chance this code is correct but I could easily be wrong. Linus, does this approach look like something you can stand? Eric Eric W. Biederman (7): proc: Rename in proc_inode rename sysctl_inodes sibling_inodes proc: Generalize proc_sys_prune_dcache into proc_prune_siblings_dcache proc: Mov rcu_read_(lock|unlock) in proc_prune_siblings_dcache proc: Use d_invalidate in proc_prune_siblings_dcache proc: Clear the pieces of proc_inode that proc_evict_inode cares about proc: Use a list of inodes to flush from proc proc: Ensure we see the exit of each process tid exactly once fs/exec.c | 5 +-- fs/proc/base.c | 111 ++++++++++++++++-------------------------------- fs/proc/inode.c | 60 +++++++++++++++++++++++--- fs/proc/internal.h | 4 +- fs/proc/proc_sysctl.c | 45 +++----------------- include/linux/pid.h | 2 + include/linux/proc_fs.h | 4 +- kernel/exit.c | 4 +- kernel/pid.c | 16 +++++++ 9 files changed, 124 insertions(+), 127 deletions(-)