From patchwork Mon Feb 21 13:15:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Haines X-Patchwork-Id: 12753629 X-Patchwork-Delegate: paul@paul-moore.com 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 B5B79C433F5 for ; Mon, 21 Feb 2022 13:15:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358737AbiBUNQS (ORCPT ); Mon, 21 Feb 2022 08:16:18 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:50062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231450AbiBUNQR (ORCPT ); Mon, 21 Feb 2022 08:16:17 -0500 Received: from sa-prd-fep-047.btinternet.com (mailomta7-sa.btinternet.com [213.120.69.13]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C90E61EEDA; Mon, 21 Feb 2022 05:15:50 -0800 (PST) Received: from sa-prd-rgout-003.btmx-prd.synchronoss.net ([10.2.38.6]) by sa-prd-fep-047.btinternet.com with ESMTP id <20220221131548.JVDQ16049.sa-prd-fep-047.btinternet.com@sa-prd-rgout-003.btmx-prd.synchronoss.net>; Mon, 21 Feb 2022 13:15:48 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=btmx201904; t=1645449348; bh=LsQkjPur9s6lfrXPc17vF8122/BSlTkt2PIKZJf+o9A=; h=From:To:Cc:Subject:Date:Message-Id:X-Mailer:MIME-Version; b=E/JiDTHJaU2tWpXNIE/w6ZYw+VbzX56ruXbhRtOawrnuUhF1pflk9lBlTNrd8ZCu7FTtFIg0WudeHkwjW0+HNnEXAgfm8iTv5WE8w9xM/P65HAysS5YZ0lCdAyD29aANmtAbMR5ax7E8zzKPM5nYI81DsY6f/cdyOFXJ7A7ykKl4x8wkfJyTL1B9VqxuDp4kMy7+GBC3WmtHS1hgsf566gEy2xW1zDOR+SpL5aRdAhq8uSb4XTOMjYsV9A9EGoCkQqDRQqJ4NEs9sLsMRexek8lY/NiTljeB4MpPFc7lzdWlOtxHdhWpX6LkVlKHsylicq0YV8ZonE+j33mGfdFang== Authentication-Results: btinternet.com; auth=pass (PLAIN) smtp.auth=richard_c_haines@btinternet.com; bimi=skipped X-SNCR-Rigid: 6139429016674C65 X-Originating-IP: [86.184.61.59] X-OWM-Source-IP: 86.184.61.59 (GB) X-OWM-Env-Sender: richard_c_haines@btinternet.com X-VadeSecure-score: verdict=clean score=0/300, class=clean X-RazorGate-Vade: gggruggvucftvghtrhhoucdtuddrgedvvddrkeeigdeglecutefuodetggdotefrodftvfcurfhrohhfihhlvgemuceutffkvffkuffjvffgnffgvefqofdpqfgfvfenuceurghilhhouhhtmecufedtudenucenucfjughrpefhvffufffkofgggfestdekredtredttdenucfhrhhomheptfhitghhrghrugcujfgrihhnvghsuceorhhitghhrghruggptggphhgrihhnvghssegsthhinhhtvghrnhgvthdrtghomheqnecuggftrfgrthhtvghrnhepheffledtuefffeffvddtgeevffetffekveeggeduhfeghedtvddvhedtkefggeeknecuffhomhgrihhnpehkvghrnhgvlhdrohhrghdpfhhigidrshgvtghurhhithihnecukfhppeekiedrudekgedriedurdehleenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhephhgvlhhopehlohgtrghlhhhoshhtrdhlohgtrghlughomhgrihhnpdhinhgvthepkeeirddukeegrdeiuddrheelpdhmrghilhhfrhhomheprhhitghhrghruggptggphhgrihhnvghssegsthhinhhtvghrnhgvthdrtghomhdpnhgspghrtghpthhtohepledprhgtphhtthhopeguvghmihhosggvnhhouhhrsehgmhgrihhlrdgtohhmpdhrtghpthhtohepvghprghrihhssehprghrihhsphhlrggtvgdrohhrghdprhgtphhtthhopehjvghffhhvsehgohhoghhlvgdrtghomhdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgt phhtthhopehprghulhesphgruhhlqdhmohhorhgvrdgtohhmpdhrtghpthhtoheprhhitghhrghruggptggphhgrihhnvghssegsthhinhhtvghrnhgvthdrtghomhdprhgtphhtthhopehsvghlihhnuhigqdhrvghfphholhhitgihsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtohepshgvlhhinhhugiesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehsthgvphhhvghnrdhsmhgrlhhlvgihrdifohhrkhesghhmrghilhdrtghomh X-RazorGate-Vade-Verdict: clean 0 X-RazorGate-Vade-Classification: clean X-SNCR-hdrdom: btinternet.com Received: from localhost.localdomain (86.184.61.59) by sa-prd-rgout-003.btmx-prd.synchronoss.net (5.8.716.04) (authenticated as richard_c_haines@btinternet.com) id 6139429016674C65; Mon, 21 Feb 2022 13:15:48 +0000 From: Richard Haines To: paul@paul-moore.com, stephen.smalley.work@gmail.com, eparis@parisplace.org, demiobenour@gmail.com Cc: selinux@vger.kernel.org, linux-kernel@vger.kernel.org, selinux-refpolicy@vger.kernel.org, jeffv@google.com, Richard Haines Subject: [PATCH V2] security/selinux: Always allow FIOCLEX and FIONCLEX Date: Mon, 21 Feb 2022 13:15:33 +0000 Message-Id: <20220221131533.74238-1-richard_c_haines@btinternet.com> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org 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 --- V2 Change: Control via a policy capability. See this thread for discussion: https://lore.kernel.org/selinux/CAHC9VhQEPxYP_KU56gAGNHKQaxucY8gSsHiUB42PVgADBAccRQ@mail.gmail.com/T/#t With this patch and the polcap enabled, the selinux-testsuite will fail: ioctl/test at line 47 - Will need a fix. security/selinux/hooks.c | 7 +++++++ security/selinux/include/policycap.h | 1 + security/selinux/include/policycap_names.h | 3 ++- security/selinux/include/security.h | 7 +++++++ 4 files changed, 17 insertions(+), 1 deletion(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 5b6895e4f..030c41652 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3745,6 +3745,13 @@ static int selinux_file_ioctl(struct file *file, unsigned int cmd, CAP_OPT_NONE, true); break; + case FIOCLEX: + case FIONCLEX: + /* Must always succeed if polcap set, else default: */ + if (selinux_policycap_ioctl_skip_cloexec()) + break; + fallthrough; + /* 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 2ec038efb..44d73dc32 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_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 b89289f09..ebd64afe1 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 ac0ece013..8a789c22b 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_CLOEXEC]); +} + struct selinux_policy_convert_data; struct selinux_load_state {