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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 5C99EC2BA83 for ; Fri, 14 Feb 2020 17:37:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3311D2168B for ; Fri, 14 Feb 2020 17:37:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581701833; bh=Yna5Ul/uCbNFqsLvuY2wZXEKPkMxhFbctsBpplspk1w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BwXlD4MXeQs+iErpskj+AmdekzzIFnKs+xBxPeN/YWPMq/CvFIEAmpiqu9uuQjH/T a3VVB6nlUwmdxLoa+xObhBqvErnnTbrw3PctSY3Gw0gToFc/glT/QiJHCoQT494P+h 9SWXlbCXcpkqFUWI97axZMPU1SWk2TQ30tvYsqQM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390662AbgBNRhM (ORCPT ); Fri, 14 Feb 2020 12:37:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:54736 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390128AbgBNQFR (ORCPT ); Fri, 14 Feb 2020 11:05:17 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4257724682; Fri, 14 Feb 2020 16:05:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581696316; bh=Yna5Ul/uCbNFqsLvuY2wZXEKPkMxhFbctsBpplspk1w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=slPy6EdPbVeTZi8PyIoCkR9Ef7PHWH3ogSInrIOFan1ga7WGZUOMc4WSjUd/6xhbj lMSkcUnUBF8Kv0pm1+3gw+ktaseL/rfrR/o9z0YHpYfVPx3ieGD5vrKRgST7RWsu6J sT8wyjpIvFn8JhCyK50vIMLMFEZvoQwLvs7DmqGw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Stephen Smalley , Will Deacon , Paul Moore , Sasha Levin , selinux@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 157/459] selinux: revert "stop passing MAY_NOT_BLOCK to the AVC upon follow_link" Date: Fri, 14 Feb 2020 10:56:47 -0500 Message-Id: <20200214160149.11681-157-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214160149.11681-1-sashal@kernel.org> References: <20200214160149.11681-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stephen Smalley [ Upstream commit 1a37079c236d55fb31ebbf4b59945dab8ec8764c ] This reverts commit e46e01eebbbc ("selinux: stop passing MAY_NOT_BLOCK to the AVC upon follow_link"). The correct fix is to instead fall back to ref-walk if audit is required irrespective of the specific audit data type. This is done in the next commit. Fixes: e46e01eebbbc ("selinux: stop passing MAY_NOT_BLOCK to the AVC upon follow_link") Reported-by: Will Deacon Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Sasha Levin --- security/selinux/avc.c | 24 ++++++++++++++++++++++-- security/selinux/hooks.c | 5 +++-- security/selinux/include/avc.h | 5 +++++ 3 files changed, 30 insertions(+), 4 deletions(-) diff --git a/security/selinux/avc.c b/security/selinux/avc.c index ecd3829996aa4..74c43ebe34bb8 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -862,8 +862,9 @@ static int avc_update_node(struct selinux_avc *avc, * permissive mode that only appear when in enforcing mode. * * See the corresponding handling in slow_avc_audit(), and the - * logic in selinux_inode_permission for the MAY_NOT_BLOCK flag, - * which is transliterated into AVC_NONBLOCKING. + * logic in selinux_inode_follow_link and selinux_inode_permission + * for the VFS MAY_NOT_BLOCK flag, which is transliterated into + * AVC_NONBLOCKING for avc_has_perm_noaudit(). */ if (flags & AVC_NONBLOCKING) return 0; @@ -1205,6 +1206,25 @@ int avc_has_perm(struct selinux_state *state, u32 ssid, u32 tsid, u16 tclass, return rc; } +int avc_has_perm_flags(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, u32 requested, + struct common_audit_data *auditdata, + int flags) +{ + struct av_decision avd; + int rc, rc2; + + rc = avc_has_perm_noaudit(state, ssid, tsid, tclass, requested, + (flags & MAY_NOT_BLOCK) ? AVC_NONBLOCKING : 0, + &avd); + + rc2 = avc_audit(state, ssid, tsid, tclass, requested, &avd, rc, + auditdata, flags); + if (rc2) + return rc2; + return rc; +} + u32 avc_policy_seqno(struct selinux_state *state) { return state->avc->avc_cache.latest_notif; diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 9625b99e677fd..9943539457906 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3008,8 +3008,9 @@ static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, if (IS_ERR(isec)) return PTR_ERR(isec); - return avc_has_perm(&selinux_state, - sid, isec->sid, isec->sclass, FILE__READ, &ad); + return avc_has_perm_flags(&selinux_state, + sid, isec->sid, isec->sclass, FILE__READ, &ad, + rcu ? MAY_NOT_BLOCK : 0); } static noinline int audit_inode_permission(struct inode *inode, diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h index 7be0e1e90e8be..74ea50977c201 100644 --- a/security/selinux/include/avc.h +++ b/security/selinux/include/avc.h @@ -153,6 +153,11 @@ int avc_has_perm(struct selinux_state *state, u32 ssid, u32 tsid, u16 tclass, u32 requested, struct common_audit_data *auditdata); +int avc_has_perm_flags(struct selinux_state *state, + u32 ssid, u32 tsid, + u16 tclass, u32 requested, + struct common_audit_data *auditdata, + int flags); int avc_has_extended_perms(struct selinux_state *state, u32 ssid, u32 tsid, u16 tclass, u32 requested, -- 2.20.1