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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 0A933C10F11 for ; Wed, 24 Apr 2019 17:37:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE9EB21904 for ; Wed, 24 Apr 2019 17:37:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556127420; bh=Dq7ld1LdbcEflohjCoyQ7jz+RRaPMZc7jZJTC+2y9bI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=h+5BINYxI4Q+sSRn19vRe5SQwbvtr2ul4x3uFtfazFlNzThLjJEiyvBfnv8AXoi6P EYnwJ0OfcuDOd/QdfE0a3bFtt7R9ht1DrA4p2Mjqo8oWAF/prxS0JXpO5SImSERf+0 zB5WDf0d69QO801CU+vvv3vyDLqo1vEImXZYtgdQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403937AbfDXRg7 (ORCPT ); Wed, 24 Apr 2019 13:36:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:35752 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391535AbfDXRgy (ORCPT ); Wed, 24 Apr 2019 13:36:54 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C1F3521907; Wed, 24 Apr 2019 17:36:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556127413; bh=Dq7ld1LdbcEflohjCoyQ7jz+RRaPMZc7jZJTC+2y9bI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pEiLGcn4LIdj6Ap+Qoz1llqSSajFbC+8wyGjxhjEUeZTV2lUILiIE3oA0MyhxgaAO slM+8Nqvl/gKPHMXxGQOPS6l8cJXc3QbU/Wwq4dGj7ESdQ/oFHSEIb131MtHXU4Vlg 44OdR6poGAPbN99B20DPN2mLlThw+rlbNUZyybRs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Konstantin Khlebnikov , Corey Minyard , Yang Yingliang Subject: [PATCH 5.0 083/115] ipmi: fix sleep-in-atomic in free_user at cleanup SRCU user->release_barrier Date: Wed, 24 Apr 2019 19:10:19 +0200 Message-Id: <20190424170929.794865018@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170924.797924502@linuxfoundation.org> References: <20190424170924.797924502@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Corey Minyard commit 3b9a907223d7f6b9d1dadea29436842ae9bcd76d upstream. free_user() could be called in atomic context. This patch pushed the free operation off into a workqueue. Example: BUG: sleeping function called from invalid context at kernel/workqueue.c:2856 in_atomic(): 1, irqs_disabled(): 0, pid: 177, name: ksoftirqd/27 CPU: 27 PID: 177 Comm: ksoftirqd/27 Not tainted 4.19.25-3 #1 Hardware name: AIC 1S-HV26-08/MB-DPSB04-06, BIOS IVYBV060 10/21/2015 Call Trace: dump_stack+0x5c/0x7b ___might_sleep+0xec/0x110 __flush_work+0x48/0x1f0 ? try_to_del_timer_sync+0x4d/0x80 _cleanup_srcu_struct+0x104/0x140 free_user+0x18/0x30 [ipmi_msghandler] ipmi_free_recv_msg+0x3a/0x50 [ipmi_msghandler] deliver_response+0xbd/0xd0 [ipmi_msghandler] deliver_local_response+0xe/0x30 [ipmi_msghandler] handle_one_recv_msg+0x163/0xc80 [ipmi_msghandler] ? dequeue_entity+0xa0/0x960 handle_new_recv_msgs+0x15c/0x1f0 [ipmi_msghandler] tasklet_action_common.isra.22+0x103/0x120 __do_softirq+0xf8/0x2d7 run_ksoftirqd+0x26/0x50 smpboot_thread_fn+0x11d/0x1e0 kthread+0x103/0x140 ? sort_range+0x20/0x20 ? kthread_destroy_worker+0x40/0x40 ret_from_fork+0x1f/0x40 Fixes: 77f8269606bf ("ipmi: fix use-after-free of user->release_barrier.rda") Reported-by: Konstantin Khlebnikov Signed-off-by: Corey Minyard Cc: stable@vger.kernel.org # 5.0 Cc: Yang Yingliang Signed-off-by: Greg Kroah-Hartman --- drivers/char/ipmi/ipmi_msghandler.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -214,6 +214,9 @@ struct ipmi_user { /* Does this interface receive IPMI events? */ bool gets_events; + + /* Free must run in process context for RCU cleanup. */ + struct work_struct remove_work; }; static struct ipmi_user *acquire_ipmi_user(struct ipmi_user *user, int *index) @@ -1079,6 +1082,15 @@ static int intf_err_seq(struct ipmi_smi } +static void free_user_work(struct work_struct *work) +{ + struct ipmi_user *user = container_of(work, struct ipmi_user, + remove_work); + + cleanup_srcu_struct(&user->release_barrier); + kfree(user); +} + int ipmi_create_user(unsigned int if_num, const struct ipmi_user_hndl *handler, void *handler_data, @@ -1122,6 +1134,8 @@ int ipmi_create_user(unsigned int goto out_kfree; found: + INIT_WORK(&new_user->remove_work, free_user_work); + rv = init_srcu_struct(&new_user->release_barrier); if (rv) goto out_kfree; @@ -1184,8 +1198,9 @@ EXPORT_SYMBOL(ipmi_get_smi_info); static void free_user(struct kref *ref) { struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount); - cleanup_srcu_struct(&user->release_barrier); - kfree(user); + + /* SRCU cleanup must happen in task context. */ + schedule_work(&user->remove_work); } static void _ipmi_destroy_user(struct ipmi_user *user)