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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 00BC4C35250 for ; Sun, 9 Feb 2020 13:01:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC83F20733 for ; Sun, 9 Feb 2020 13:01:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581253296; bh=T87wCXW8YvEympw0ezL1a06OagvSPmkDzlrJq9KnNi4=; h=Subject:To:Cc:From:Date:List-ID:From; b=NK/g+b88dQ9jUFEXbcCxZ8SSGxQucbJtn7i1HHe7NQFzelds7Yr3c9nmnu0G44AMD SyRg3faB5z2P3nxTl2llbTR4xn9Un6dsMbqZwW5sguRmU2wKrbl0GTE4Nhuyda4YK3 csmGEkBcfD90qg+WU28zF73FxqRmiIQBSJ6P6IPE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727654AbgBINBg (ORCPT ); Sun, 9 Feb 2020 08:01:36 -0500 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:45871 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727473AbgBINBg (ORCPT ); Sun, 9 Feb 2020 08:01:36 -0500 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 34C0321E95; Sun, 9 Feb 2020 08:01:34 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Sun, 09 Feb 2020 08:01:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=1Bja3K w/hx61On6CVlWcPD9EsES7kSWd5BBy5EWYdxs=; b=PagPYA9VlIv7HRcikNmvKN Yv+8/wgqyrsQ7v4dgousUaJ4XBP8EHGKouoG2Uba1OQwZVeefxSjtIyms9tJ/mGg m9fyRGnxL++wemBQdZpjlKHdMMBZaaMTBQCx2AiOQhnKY9BjK8rsDhiOJWiPCH1w DJGBTquPxo02nNbkxzt/0RD56k9JHWLKl9lpurk43D1MKJpkXxljBohREl6KhYSu 1MN+K67BAbIO/l9Oarrj8bw+ir7imiDLjrTSaBpQp882fVBcz6jsLJcMQHi8kcQf /ZS3C33Y3OvjJpp/fb4S22/fVF7qsXppfeHZPe54HRp7D2sCq9WI3rbjz9ana+Xw == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedugedrheelgddvgecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecufghrlhcuvffnffculddqiedmnecujfgurhepuffvhf ffkfggtgfgsehtkeertddttdflnecuhfhrohhmpeeoghhrvghgkhhhsehlihhnuhigfhho uhhnuggrthhiohhnrdhorhhgqeenucfkphepfeekrdelkedrfeejrddufeehnecuvehluh hsthgvrhfuihiivgepieenucfrrghrrghmpehmrghilhhfrhhomhepghhrvghgsehkrhho rghhrdgtohhm X-ME-Proxy: Received: from localhost (unknown [38.98.37.135]) by mail.messagingengine.com (Postfix) with ESMTPA id A296630606E9; Sun, 9 Feb 2020 08:01:32 -0500 (EST) Subject: FAILED: patch "[PATCH] selinux: reorder hooks to make runtime disable less broken" failed to apply to 5.4-stable tree To: omosnace@redhat.com, paul@paul-moore.com, sds@tycho.nsa.gov Cc: From: Date: Sun, 09 Feb 2020 12:38:31 +0100 Message-ID: <158124831193255@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From cfff75d8973ae4a90b3df3ae7fbba1ce9af9c8f0 Mon Sep 17 00:00:00 2001 From: Ondrej Mosnacek Date: Wed, 8 Jan 2020 15:09:58 +0100 Subject: [PATCH] selinux: reorder hooks to make runtime disable less broken Commit b1d9e6b0646d ("LSM: Switch to lists of hooks") switched the LSM infrastructure to use per-hook lists, which meant that removing the hooks for a given module was no longer atomic. Even though the commit clearly documents that modules implementing runtime revmoval of hooks (only SELinux attempts this madness) need to take special precautions to avoid race conditions, SELinux has never addressed this. By inserting an artificial delay between the loop iterations of security_delete_hooks() (I used 100 ms), booting to a state where SELinux is enabled, but policy is not yet loaded, and running these commands: while true; do ping -c 1 ; done & echo -n 1 >/sys/fs/selinux/disable kill %1 wait ...I was able to trigger NULL pointer dereferences in various places. I also have a report of someone getting panics on a stock RHEL-8 kernel after setting SELINUX=disabled in /etc/selinux/config and rebooting (without adding "selinux=0" to kernel command-line). Reordering the SELinux hooks such that those that allocate structures are removed last seems to prevent these panics. It is very much possible that this doesn't make the runtime disable completely race-free, but at least it makes the operation much less fragile. Cc: stable@vger.kernel.org Fixes: b1d9e6b0646d ("LSM: Switch to lists of hooks") Signed-off-by: Ondrej Mosnacek Reviewed-by: Stephen Smalley Signed-off-by: Paul Moore diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index a81631f8cc5d..2c84b12d50bc 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6892,6 +6892,21 @@ static int selinux_perf_event_write(struct perf_event *event) } #endif +/* + * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order: + * 1. any hooks that don't belong to (2.) or (3.) below, + * 2. hooks that both access structures allocated by other hooks, and allocate + * structures that can be later accessed by other hooks (mostly "cloning" + * hooks), + * 3. hooks that only allocate structures that can be later accessed by other + * hooks ("allocating" hooks). + * + * Please follow block comment delimiters in the list to keep this order. + * + * This ordering is needed for SELinux runtime disable to work at least somewhat + * safely. Breaking the ordering rules above might lead to NULL pointer derefs + * when disabling SELinux at runtime. + */ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr), LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction), @@ -6914,12 +6929,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds), LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds), - LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup), - LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param), - - LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security), LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security), - LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts), LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts), LSM_HOOK_INIT(sb_remount, selinux_sb_remount), LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount), @@ -6929,12 +6939,10 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(sb_umount, selinux_umount), LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts), LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts), - LSM_HOOK_INIT(sb_add_mnt_opt, selinux_add_mnt_opt), LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security), LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as), - LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security), LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security), LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security), LSM_HOOK_INIT(inode_create, selinux_inode_create), @@ -7006,21 +7014,15 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission), LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid), - LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security), - - LSM_HOOK_INIT(msg_queue_alloc_security, - selinux_msg_queue_alloc_security), LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate), LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl), LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd), LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv), - LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security), LSM_HOOK_INIT(shm_associate, selinux_shm_associate), LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl), LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat), - LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security), LSM_HOOK_INIT(sem_associate, selinux_sem_associate), LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl), LSM_HOOK_INIT(sem_semop, selinux_sem_semop), @@ -7031,13 +7033,11 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(setprocattr, selinux_setprocattr), LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel), - LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx), LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid), LSM_HOOK_INIT(release_secctx, selinux_release_secctx), LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx), LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx), LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx), - LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx), LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect), LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send), @@ -7060,7 +7060,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(socket_getpeersec_stream, selinux_socket_getpeersec_stream), LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram), - LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security), LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security), LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security), LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid), @@ -7075,7 +7074,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc), LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec), LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow), - LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security), LSM_HOOK_INIT(tun_dev_free_security, selinux_tun_dev_free_security), LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create), LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue), @@ -7085,17 +7083,11 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access), LSM_HOOK_INIT(ib_endport_manage_subnet, selinux_ib_endport_manage_subnet), - LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security), LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security), #endif #ifdef CONFIG_SECURITY_NETWORK_XFRM - LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc), - LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone), LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free), LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete), - LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc), - LSM_HOOK_INIT(xfrm_state_alloc_acquire, - selinux_xfrm_state_alloc_acquire), LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free), LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete), LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup), @@ -7105,14 +7097,12 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { #endif #ifdef CONFIG_KEYS - LSM_HOOK_INIT(key_alloc, selinux_key_alloc), LSM_HOOK_INIT(key_free, selinux_key_free), LSM_HOOK_INIT(key_permission, selinux_key_permission), LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity), #endif #ifdef CONFIG_AUDIT - LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init), LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known), LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match), LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free), @@ -7122,21 +7112,66 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(bpf, selinux_bpf), LSM_HOOK_INIT(bpf_map, selinux_bpf_map), LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog), - LSM_HOOK_INIT(bpf_map_alloc_security, selinux_bpf_map_alloc), - LSM_HOOK_INIT(bpf_prog_alloc_security, selinux_bpf_prog_alloc), LSM_HOOK_INIT(bpf_map_free_security, selinux_bpf_map_free), LSM_HOOK_INIT(bpf_prog_free_security, selinux_bpf_prog_free), #endif #ifdef CONFIG_PERF_EVENTS LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open), - LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc), LSM_HOOK_INIT(perf_event_free, selinux_perf_event_free), LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read), LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write), #endif LSM_HOOK_INIT(locked_down, selinux_lockdown), + + /* + * PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE + */ + LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup), + LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param), + LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts), + LSM_HOOK_INIT(sb_add_mnt_opt, selinux_add_mnt_opt), +#ifdef CONFIG_SECURITY_NETWORK_XFRM + LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone), +#endif + + /* + * PUT "ALLOCATING" HOOKS HERE + */ + LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security), + LSM_HOOK_INIT(msg_queue_alloc_security, + selinux_msg_queue_alloc_security), + LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security), + LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security), + LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security), + LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security), + LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx), + LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx), + LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security), + LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security), +#ifdef CONFIG_SECURITY_INFINIBAND + LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security), +#endif +#ifdef CONFIG_SECURITY_NETWORK_XFRM + LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc), + LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc), + LSM_HOOK_INIT(xfrm_state_alloc_acquire, + selinux_xfrm_state_alloc_acquire), +#endif +#ifdef CONFIG_KEYS + LSM_HOOK_INIT(key_alloc, selinux_key_alloc), +#endif +#ifdef CONFIG_AUDIT + LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init), +#endif +#ifdef CONFIG_BPF_SYSCALL + LSM_HOOK_INIT(bpf_map_alloc_security, selinux_bpf_map_alloc), + LSM_HOOK_INIT(bpf_prog_alloc_security, selinux_bpf_prog_alloc), +#endif +#ifdef CONFIG_PERF_EVENTS + LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc), +#endif }; static __init int selinux_init(void) @@ -7315,14 +7350,18 @@ int selinux_disable(struct selinux_state *state) pr_info("SELinux: Disabled at runtime.\n"); + /* + * Unregister netfilter hooks. + * Must be done before security_delete_hooks() to avoid breaking + * runtime disable. + */ + selinux_nf_ip_exit(); + security_delete_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks)); /* Try to destroy the avc node cache */ avc_disable(); - /* Unregister netfilter hooks. */ - selinux_nf_ip_exit(); - /* Unregister selinuxfs. */ exit_sel_fs();