From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D771C43441 for ; Fri, 16 Nov 2018 17:34:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4BD462086A for ; Fri, 16 Nov 2018 17:34:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4BD462086A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390199AbeKQDrg (ORCPT ); Fri, 16 Nov 2018 22:47:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34864 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729140AbeKQDrf (ORCPT ); Fri, 16 Nov 2018 22:47:35 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AD50458E27; Fri, 16 Nov 2018 17:34:18 +0000 (UTC) Received: from madcap2.tricolour.ca (ovpn-112-24.phx2.redhat.com [10.3.112.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9A04960E1C; Fri, 16 Nov 2018 17:34:12 +0000 (UTC) From: Richard Guy Briggs To: linux-fsdevel@vger.kernel.org, viro@ZenIV.linux.org.uk, LKML , Linux-Audit Mailing List Cc: Paul Moore , Eric Paris , Steve Grubb , Richard Guy Briggs Subject: [RFC PATCH ghak100 V1 2/2] audit: moar filter PATH records keyed on filesystem magic Date: Fri, 16 Nov 2018 12:33:14 -0500 Message-Id: <208a86c97cd93181ffd7db2e5f95da012ab41a48.1542149969.git.rgb@redhat.com> In-Reply-To: References: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 16 Nov 2018 17:34:18 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Like 42d5e37654e4 ("audit: filter PATH records keyed on filesystem magic") Any user or remote filesystem could become unavailable and effectively block on a forced unmount. -a always,exit -S umount2 -F key=umount2 Provide a method to ignore these user and remote filesystems to prevent them from being impossible to unmount. Extend the "AUDIT_FILTER_FS" filter that uses the field type AUDIT_FSTYPE keying off the filesystem 4-octet hexadecimal magic identifier to filter specific filesystems to cover audit_inode() to address this blockage. An example rule would look like: -a never,filesystem -F fstype=0x517B -F key=ignore_smb -a never,filesystem -F fstype=0x6969 -F key=ignore_nfs Arguably the better way to address this issue is to disable auditing processes that touch removable filesystems. Please see the github issue tracker https://github.com/linux-audit/audit-kernel/issues/100 Signed-off-by: Richard Guy Briggs --- kernel/auditsc.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index d39a7fbaf944..59d6d3fbc00e 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1777,10 +1777,33 @@ void __audit_inode(struct filename *name, const struct dentry *dentry, struct inode *inode = d_backing_inode(dentry); struct audit_names *n; bool parent = flags & AUDIT_INODE_PARENT; + struct audit_entry *e; + struct list_head *list = &audit_filter_list[AUDIT_FILTER_FS]; + int i; if (!context->in_syscall) return; + rcu_read_lock(); + if (!list_empty(list)) { + list_for_each_entry_rcu(e, list, list) { + for (i = 0; i < e->rule.field_count; i++) { + struct audit_field *f = &e->rule.fields[i]; + + if (f->type == AUDIT_FSTYPE) { + if (audit_comparator(inode->i_sb->s_magic, + f->op, f->val)) { + if (e->rule.action == AUDIT_NEVER) { + rcu_read_unlock(); + return; + } + } + } + } + } + } + rcu_read_unlock(); + if (!name) goto out_alloc; -- 1.8.3.1