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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 74D18C10F06 for ; Mon, 11 Mar 2019 10:02:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 45512206BA for ; Mon, 11 Mar 2019 10:02:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=yandex-team.ru header.i=@yandex-team.ru header.b="gzLaBMGV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727017AbfCKKCe (ORCPT ); Mon, 11 Mar 2019 06:02:34 -0400 Received: from forwardcorp1o.cmail.yandex.net ([37.9.109.47]:58438 "EHLO forwardcorp1o.cmail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725839AbfCKKCd (ORCPT ); Mon, 11 Mar 2019 06:02:33 -0400 Received: from mxbackcorp1j.mail.yandex.net (mxbackcorp1j.mail.yandex.net [IPv6:2a02:6b8:0:1619::162]) by forwardcorp1o.cmail.yandex.net (Yandex) with ESMTP id D6ECE205E0; Mon, 11 Mar 2019 13:02:29 +0300 (MSK) Received: from smtpcorp1o.mail.yandex.net (smtpcorp1o.mail.yandex.net [2a02:6b8:0:1a2d::30]) by mxbackcorp1j.mail.yandex.net (nwsmtp/Yandex) with ESMTP id JrUCVOqw5h-2TcC7Ndu; Mon, 11 Mar 2019 13:02:29 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1552298549; bh=0Nl5RUqGqBoHR8d4vM2L3KFvc1aFhwpXjS6QTRLHBCw=; h=Message-ID:Date:To:From:Subject:Cc; b=gzLaBMGVH2S4hMIjfpxs0s4dJfOluWysq1Z/CmXT0ufv/lxHkOBjcm1c2fyqm4pzF rgypg8HOqlGKkmeuCFQvE8nsLHF9iICM3v7o8B7/mTHuJlu94snOJo6y2CxXyLRD9k 6arJYhZSL0HPKvBZe0N+N2xybEwCu+ydGEc/BLGg= Authentication-Results: mxbackcorp1j.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-red.dhcp.yndx.net (dynamic-red.dhcp.yndx.net [2a02:6b8:0:40c:65e1:a124:95f1:7d47]) by smtpcorp1o.mail.yandex.net (nwsmtp/Yandex) with ESMTPSA id fqNSc8UXGO-2T4iVBRW; Mon, 11 Mar 2019 13:02:29 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client certificate not present) Subject: [PATCH] ipmi: fix sleep-in-atomic in free_user at cleanup SRCU user->release_barrier From: Konstantin Khlebnikov To: openipmi-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, Corey Minyard , Yang Yingliang Cc: stable@vger.kernel.org Date: Mon, 11 Mar 2019 13:02:29 +0300 Message-ID: <155229854905.2133.15708039732382992559.stgit@buzz> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org free_user() could be called in atomic context. This patch uses non-sleeping cleanup_srcu_struct_quiesced(). At this stage atomic refcount is zero, thus all read-sections should have been ended. 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") Signed-off-by: Konstantin Khlebnikov Cc: stable@vger.kernel.org # 4.18 Cc: Yang Yingliang Cc: Corey Minyard --- drivers/char/ipmi/ipmi_msghandler.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index e8ba67834746..c35f2bcbaa23 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -1260,7 +1260,12 @@ 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); + + /* + * Cleanup without waiting. This could be called in atomic context. + * Refcount is zero: all read-sections should have been ended. + */ + cleanup_srcu_struct_quiesced(&user->release_barrier); kfree(user); }