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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E835C433FE for ; Tue, 5 Apr 2022 13:23:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379307AbiDENNn (ORCPT ); Tue, 5 Apr 2022 09:13:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344256AbiDEJTC (ORCPT ); Tue, 5 Apr 2022 05:19:02 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8929B49929; Tue, 5 Apr 2022 02:06:22 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3CB4CB818F3; Tue, 5 Apr 2022 09:06:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9EFBAC385A1; Tue, 5 Apr 2022 09:06:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649149580; bh=YQBBt348QczuErmBCnsCv2Z8g7AXEkgPfyVRGt2m8CM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pS5HMSq6hORKsUOeSudsTlf6284ZVXk20m6eO6f/88lRQF0+u4C/kKEZRQZdpooWu HDZtEEtdoQpAL7JrkYzg5niMtScpf/rkINtsEBOZ9neZUAIXoKr2LHo6JAPszuGP1A adnzhO4hUG8ttxcAJwi9hkuOJzwBWRdwRso5uIQo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Richard Haines , Paul Moore , Sasha Levin , Demi Marie Obenour Subject: [PATCH 5.16 0767/1017] selinux: allow FIOCLEX and FIONCLEX with policy capability Date: Tue, 5 Apr 2022 09:28:00 +0200 Message-Id: <20220405070417.028121434@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Richard Haines [ Upstream commit 65881e1db4e948614d9eb195b8e1197339822949 ] These ioctls are equivalent to fcntl(fd, F_SETFD, flags), which SELinux always allows too. Furthermore, a failed FIOCLEX could result in a file descriptor being leaked to a process that should not have access to it. As this patch removes access controls, a policy capability needs to be enabled in policy to always allow these ioctls. Based-on-patch-by: Demi Marie Obenour Signed-off-by: Richard Haines [PM: subject line tweak] Signed-off-by: Paul Moore Signed-off-by: Sasha Levin --- security/selinux/hooks.c | 6 ++++++ security/selinux/include/policycap.h | 1 + security/selinux/include/policycap_names.h | 3 ++- security/selinux/include/security.h | 7 +++++++ 4 files changed, 16 insertions(+), 1 deletion(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 69b0709bd156..94ef617de9d0 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3800,6 +3800,12 @@ static int selinux_file_ioctl(struct file *file, unsigned int cmd, CAP_OPT_NONE, true); break; + case FIOCLEX: + case FIONCLEX: + if (!selinux_policycap_ioctl_skip_cloexec()) + error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); + break; + /* default case assumes that the command will go * to the file's ioctl() function. */ diff --git a/security/selinux/include/policycap.h b/security/selinux/include/policycap.h index 2ec038efbb03..a9e572ca4fd9 100644 --- a/security/selinux/include/policycap.h +++ b/security/selinux/include/policycap.h @@ -11,6 +11,7 @@ enum { POLICYDB_CAPABILITY_CGROUPSECLABEL, POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION, POLICYDB_CAPABILITY_GENFS_SECLABEL_SYMLINKS, + POLICYDB_CAPABILITY_IOCTL_SKIP_CLOEXEC, __POLICYDB_CAPABILITY_MAX }; #define POLICYDB_CAPABILITY_MAX (__POLICYDB_CAPABILITY_MAX - 1) diff --git a/security/selinux/include/policycap_names.h b/security/selinux/include/policycap_names.h index b89289f092c9..ebd64afe1def 100644 --- a/security/selinux/include/policycap_names.h +++ b/security/selinux/include/policycap_names.h @@ -12,7 +12,8 @@ const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = { "always_check_network", "cgroup_seclabel", "nnp_nosuid_transition", - "genfs_seclabel_symlinks" + "genfs_seclabel_symlinks", + "ioctl_skip_cloexec" }; #endif /* _SELINUX_POLICYCAP_NAMES_H_ */ diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index ac0ece01305a..c0d966020ebd 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -219,6 +219,13 @@ static inline bool selinux_policycap_genfs_seclabel_symlinks(void) return READ_ONCE(state->policycap[POLICYDB_CAPABILITY_GENFS_SECLABEL_SYMLINKS]); } +static inline bool selinux_policycap_ioctl_skip_cloexec(void) +{ + struct selinux_state *state = &selinux_state; + + return READ_ONCE(state->policycap[POLICYDB_CAPABILITY_IOCTL_SKIP_CLOEXEC]); +} + struct selinux_policy_convert_data; struct selinux_load_state { -- 2.34.1