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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 78B0AC433DF for ; Mon, 17 Aug 2020 16:31:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 532B8204FD for ; Mon, 17 Aug 2020 16:31:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597681880; bh=LIxqRBPcvOoUtOkQW4c43VrIb8itUKAS0rSS5ci8yC0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Pe4tyQ/cm+yhO5HdE/t0U95mKTHFk3DSilFlUOHO99hus/Kh0/4z0EmJgvrkPYLAu v9v/d33peqGNVsQGiZvHnIDQWNtIkynqR8BfbjWj34Dv4mEmJY88MHRWLRAWdMtQb2 YiO55Em9PtANzc7yO/cSrqdOIiD+5hpAOAMX5//c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731260AbgHQQbQ (ORCPT ); Mon, 17 Aug 2020 12:31:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:41830 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387980AbgHQPyV (ORCPT ); Mon, 17 Aug 2020 11:54:21 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 86D8F2245C; Mon, 17 Aug 2020 15:54:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597679660; bh=LIxqRBPcvOoUtOkQW4c43VrIb8itUKAS0rSS5ci8yC0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L6mzhF5jEqDiO2ZVdoT6yJvgPlp3lzRQn0YB8avHUK4SbuxEjvB33J12ZXBXxZVaD XxZUzUNqEjj3GoQl0qAucmtHIO+2lz5y8jWjhORl9R4rtafvnsllRiypQOZe5xodN5 tHqoF3odPdCyMiisLYyq9WZHi7NsiU5feG44gHFs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Abhishek Pandit-Subedi , Miao-chen Chou , Marcel Holtmann , Sasha Levin Subject: [PATCH 5.7 259/393] Bluetooth: Fix suspend notifier race Date: Mon, 17 Aug 2020 17:15:09 +0200 Message-Id: <20200817143832.174128402@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143819.579311991@linuxfoundation.org> References: <20200817143819.579311991@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: Abhishek Pandit-Subedi [ Upstream commit 4e8c36c3b0d73d46aa27cfd4308aaa445a1067df ] Unregister from suspend notifications and cancel suspend preparations before running hci_dev_do_close. Otherwise, the suspend notifier may race with unregister and cause cmd_timeout even after hdev has been freed. Below is the trace from when this panic was seen: [ 832.578518] Bluetooth: hci_core.c:hci_cmd_timeout() hci0: command 0x0c05 tx timeout [ 832.586200] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 832.586203] #PF: supervisor read access in kernel mode [ 832.586205] #PF: error_code(0x0000) - not-present page [ 832.586206] PGD 0 P4D 0 [ 832.586210] PM: suspend exit [ 832.608870] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 832.613232] CPU: 3 PID: 10755 Comm: kworker/3:7 Not tainted 5.4.44-04894-g1e9dbb96a161 #1 [ 832.630036] Workqueue: events hci_cmd_timeout [bluetooth] [ 832.630046] RIP: 0010:__queue_work+0xf0/0x374 [ 832.630051] RSP: 0018:ffff9b5285f1fdf8 EFLAGS: 00010046 [ 832.674033] RAX: ffff8a97681bac00 RBX: 0000000000000000 RCX: ffff8a976a000600 [ 832.681162] RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff8a976a000748 [ 832.688289] RBP: ffff9b5285f1fe38 R08: 0000000000000000 R09: ffff8a97681bac00 [ 832.695418] R10: 0000000000000002 R11: ffff8a976a0006d8 R12: ffff8a9745107600 [ 832.698045] usb 1-6: new full-speed USB device number 119 using xhci_hcd [ 832.702547] R13: ffff8a9673658850 R14: 0000000000000040 R15: 000000000000001e [ 832.702549] FS: 0000000000000000(0000) GS:ffff8a976af80000(0000) knlGS:0000000000000000 [ 832.702550] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 832.702550] CR2: 0000000000000000 CR3: 000000010415a000 CR4: 00000000003406e0 [ 832.702551] Call Trace: [ 832.702558] queue_work_on+0x3f/0x68 [ 832.702562] process_one_work+0x1db/0x396 [ 832.747397] worker_thread+0x216/0x375 [ 832.751147] kthread+0x138/0x140 [ 832.754377] ? pr_cont_work+0x58/0x58 [ 832.758037] ? kthread_blkcg+0x2e/0x2e [ 832.761787] ret_from_fork+0x22/0x40 [ 832.846191] ---[ end trace fa93f466da517212 ]--- Fixes: 9952d90ea2885 ("Bluetooth: Handle PM_SUSPEND_PREPARE and PM_POST_SUSPEND") Signed-off-by: Abhishek Pandit-Subedi Reviewed-by: Miao-chen Chou Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- net/bluetooth/hci_core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 4e5ecc2c9602d..c17e1a3e8218c 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -3597,9 +3597,10 @@ void hci_unregister_dev(struct hci_dev *hdev) cancel_work_sync(&hdev->power_on); - hci_dev_do_close(hdev); - unregister_pm_notifier(&hdev->suspend_notifier); + cancel_work_sync(&hdev->suspend_prepare); + + hci_dev_do_close(hdev); if (!test_bit(HCI_INIT, &hdev->flags) && !hci_dev_test_flag(hdev, HCI_SETUP) && -- 2.25.1