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[23.128.96.18]) by mx.google.com with ESMTP id oa13si282348pjb.49.2022.01.24.12.07.06; Mon, 24 Jan 2022 12:07:19 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=Jaa5jmhz; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346303AbiAXTFT (ORCPT + 99 others); Mon, 24 Jan 2022 14:05:19 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:53666 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343848AbiAXS5w (ORCPT ); Mon, 24 Jan 2022 13:57:52 -0500 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 382A2B81243; Mon, 24 Jan 2022 18:57:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D0B8C340EC; Mon, 24 Jan 2022 18:57:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643050669; bh=tvYs1VSePffa4h5x8YjWrQTm+RhMLjGYNBC6EzBNKdU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jaa5jmhznhj5/G8HnXTwnxiQelejV1z3GQSMwUiloxIwjEFFpKXui35xVCFuyxRlN 9+fgF8WVVd7w7wg7GqZzadaQY7SzQYpPP/Y6BrN7vv+HzCkl3YT6A7SPF/KccJ0P20 DbqXEqkWVoV8edGoL84qzdm1o5n7m1bvYNCOd4cg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Aring , David Teigland , Sasha Levin Subject: [PATCH 4.9 074/157] fs: dlm: filter user dlm messages for kernel locks Date: Mon, 24 Jan 2022 19:42:44 +0100 Message-Id: <20220124183935.136173920@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183932.787526760@linuxfoundation.org> References: <20220124183932.787526760@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: Alexander Aring [ Upstream commit 6c2e3bf68f3e5e5a647aa52be246d5f552d7496d ] This patch fixes the following crash by receiving a invalid message: [ 160.672220] ================================================================== [ 160.676206] BUG: KASAN: user-memory-access in dlm_user_add_ast+0xc3/0x370 [ 160.679659] Read of size 8 at addr 00000000deadbeef by task kworker/u32:13/319 [ 160.681447] [ 160.681824] CPU: 10 PID: 319 Comm: kworker/u32:13 Not tainted 5.14.0-rc2+ #399 [ 160.683472] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.14.0-1.module+el8.6.0+12648+6ede71a5 04/01/2014 [ 160.685574] Workqueue: dlm_recv process_recv_sockets [ 160.686721] Call Trace: [ 160.687310] dump_stack_lvl+0x56/0x6f [ 160.688169] ? dlm_user_add_ast+0xc3/0x370 [ 160.689116] kasan_report.cold.14+0x116/0x11b [ 160.690138] ? dlm_user_add_ast+0xc3/0x370 [ 160.690832] dlm_user_add_ast+0xc3/0x370 [ 160.691502] _receive_unlock_reply+0x103/0x170 [ 160.692241] _receive_message+0x11df/0x1ec0 [ 160.692926] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 160.693700] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 160.694427] ? lock_acquire+0x175/0x400 [ 160.695058] ? do_purge.isra.51+0x200/0x200 [ 160.695744] ? lock_acquired+0x360/0x5d0 [ 160.696400] ? lock_contended+0x6a0/0x6a0 [ 160.697055] ? lock_release+0x21d/0x5e0 [ 160.697686] ? lock_is_held_type+0xe0/0x110 [ 160.698352] ? lock_is_held_type+0xe0/0x110 [ 160.699026] ? ___might_sleep+0x1cc/0x1e0 [ 160.699698] ? dlm_wait_requestqueue+0x94/0x140 [ 160.700451] ? dlm_process_requestqueue+0x240/0x240 [ 160.701249] ? down_write_killable+0x2b0/0x2b0 [ 160.701988] ? do_raw_spin_unlock+0xa2/0x130 [ 160.702690] dlm_receive_buffer+0x1a5/0x210 [ 160.703385] dlm_process_incoming_buffer+0x726/0x9f0 [ 160.704210] receive_from_sock+0x1c0/0x3b0 [ 160.704886] ? dlm_tcp_shutdown+0x30/0x30 [ 160.705561] ? lock_acquire+0x175/0x400 [ 160.706197] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 160.706941] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 160.707681] process_recv_sockets+0x32/0x40 [ 160.708366] process_one_work+0x55e/0xad0 [ 160.709045] ? pwq_dec_nr_in_flight+0x110/0x110 [ 160.709820] worker_thread+0x65/0x5e0 [ 160.710423] ? process_one_work+0xad0/0xad0 [ 160.711087] kthread+0x1ed/0x220 [ 160.711628] ? set_kthread_struct+0x80/0x80 [ 160.712314] ret_from_fork+0x22/0x30 The issue is that we received a DLM message for a user lock but the destination lock is a kernel lock. Note that the address which is trying to derefence is 00000000deadbeef, which is in a kernel lock lkb->lkb_astparam, this field should never be derefenced by the DLM kernel stack. In case of a user lock lkb->lkb_astparam is lkb->lkb_ua (memory is shared by a union field). The struct lkb_ua will be handled by the DLM kernel stack but on a kernel lock it will contain invalid data and ends in most likely crashing the kernel. It can be reproduced with two cluster nodes. node 2: dlm_tool join test echo "862 fooobaar 1 2 1" > /sys/kernel/debug/dlm/test_locks echo "862 3 1" > /sys/kernel/debug/dlm/test_waiters node 1: dlm_tool join test python: foo = DLM(h_cmd=3, o_nextcmd=1, h_nodeid=1, h_lockspace=0x77222027, \ m_type=7, m_flags=0x1, m_remid=0x862, m_result=0xFFFEFFFE) newFile = open("/sys/kernel/debug/dlm/comms/2/rawmsg", "wb") newFile.write(bytes(foo)) Signed-off-by: Alexander Aring Signed-off-by: David Teigland Signed-off-by: Sasha Levin --- fs/dlm/lock.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index 3a7f401e943c1..ffab7dc881574 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -3975,6 +3975,14 @@ static int validate_message(struct dlm_lkb *lkb, struct dlm_message *ms) int from = ms->m_header.h_nodeid; int error = 0; + /* currently mixing of user/kernel locks are not supported */ + if (ms->m_flags & DLM_IFL_USER && ~lkb->lkb_flags & DLM_IFL_USER) { + log_error(lkb->lkb_resource->res_ls, + "got user dlm message for a kernel lock"); + error = -EINVAL; + goto out; + } + switch (ms->m_type) { case DLM_MSG_CONVERT: case DLM_MSG_UNLOCK: @@ -4003,6 +4011,7 @@ static int validate_message(struct dlm_lkb *lkb, struct dlm_message *ms) error = -EINVAL; } +out: if (error) log_error(lkb->lkb_resource->res_ls, "ignore invalid message %d from %d %x %x %x %d", -- 2.34.1