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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 C8C78C43603 for ; Tue, 10 Dec 2019 22:31:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9923B20836 for ; Tue, 10 Dec 2019 22:31:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576017101; bh=/wr7f69ycqZFhinrnrv4t11zWCsbzEx6MAndDAn+BlU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vfMmiJvROWxhHIb+Ig3zf/3brLFX6pJ/yMMpuyndyTtNAoW2gocglOSkkKQWeFe1N ajNSN2EiOoDgSe/5CVQqwTiQ13TFWVjQM4OagTZ8iN9ox3WdtKC921oaCPfnYTC3IL efLUl8VhgaD1Xfe6WGm/aplaOIpDb3rkanAFgSeA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728425AbfLJWbk (ORCPT ); Tue, 10 Dec 2019 17:31:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:51538 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728511AbfLJWb3 (ORCPT ); Tue, 10 Dec 2019 17:31:29 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 06B45214D8; Tue, 10 Dec 2019 22:31:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576017088; bh=/wr7f69ycqZFhinrnrv4t11zWCsbzEx6MAndDAn+BlU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dtAS5RgnUW2aVG6VF98PBNutMj/81dnvzdVT+u9d96ucH6sGEo8Ml6/6FXH1+AJ6O BdWpGh6dj6oluxu3J5czlSAN607naGLG5fliz3EsXb+zLs3PlnkrER40/9iqte7K+c cyYQ1R/4GIm68NNSO0NomTVQKGLNHmtsGYrzmb3I= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: John Garry , Jens Axboe , Sasha Levin , linux-ide@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 44/91] libata: Ensure ata_port probe has completed before detach Date: Tue, 10 Dec 2019 17:29:48 -0500 Message-Id: <20191210223035.14270-44-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191210223035.14270-1-sashal@kernel.org> References: <20191210223035.14270-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: John Garry [ Upstream commit 130f4caf145c3562108b245a576db30b916199d2 ] With CONFIG_DEBUG_TEST_DRIVER_REMOVE set, we may find the following WARN: [ 23.452574] ------------[ cut here ]------------ [ 23.457190] WARNING: CPU: 59 PID: 1 at drivers/ata/libata-core.c:6676 ata_host_detach+0x15c/0x168 [ 23.466047] Modules linked in: [ 23.469092] CPU: 59 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc1-00010-g5b83fd27752b-dirty #296 [ 23.477776] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI RC0 - V1.16.01 03/15/2019 [ 23.486286] pstate: a0c00009 (NzCv daif +PAN +UAO) [ 23.491065] pc : ata_host_detach+0x15c/0x168 [ 23.495322] lr : ata_host_detach+0x88/0x168 [ 23.499491] sp : ffff800011cabb50 [ 23.502792] x29: ffff800011cabb50 x28: 0000000000000007 [ 23.508091] x27: ffff80001137f068 x26: ffff8000112c0c28 [ 23.513390] x25: 0000000000003848 x24: ffff0023ea185300 [ 23.518689] x23: 0000000000000001 x22: 00000000000014c0 [ 23.523987] x21: 0000000000013740 x20: ffff0023bdc20000 [ 23.529286] x19: 0000000000000000 x18: 0000000000000004 [ 23.534584] x17: 0000000000000001 x16: 00000000000000f0 [ 23.539883] x15: ffff0023eac13790 x14: ffff0023eb76c408 [ 23.545181] x13: 0000000000000000 x12: ffff0023eac13790 [ 23.550480] x11: ffff0023eb76c228 x10: 0000000000000000 [ 23.555779] x9 : ffff0023eac13798 x8 : 0000000040000000 [ 23.561077] x7 : 0000000000000002 x6 : 0000000000000001 [ 23.566376] x5 : 0000000000000002 x4 : 0000000000000000 [ 23.571674] x3 : ffff0023bf08a0bc x2 : 0000000000000000 [ 23.576972] x1 : 3099674201f72700 x0 : 0000000000400284 [ 23.582272] Call trace: [ 23.584706] ata_host_detach+0x15c/0x168 [ 23.588616] ata_pci_remove_one+0x10/0x18 [ 23.592615] ahci_remove_one+0x20/0x40 [ 23.596356] pci_device_remove+0x3c/0xe0 [ 23.600267] really_probe+0xdc/0x3e0 [ 23.603830] driver_probe_device+0x58/0x100 [ 23.608000] device_driver_attach+0x6c/0x90 [ 23.612169] __driver_attach+0x84/0xc8 [ 23.615908] bus_for_each_dev+0x74/0xc8 [ 23.619730] driver_attach+0x20/0x28 [ 23.623292] bus_add_driver+0x148/0x1f0 [ 23.627115] driver_register+0x60/0x110 [ 23.630938] __pci_register_driver+0x40/0x48 [ 23.635199] ahci_pci_driver_init+0x20/0x28 [ 23.639372] do_one_initcall+0x5c/0x1b0 [ 23.643199] kernel_init_freeable+0x1a4/0x24c [ 23.647546] kernel_init+0x10/0x108 [ 23.651023] ret_from_fork+0x10/0x18 [ 23.654590] ---[ end trace 634a14b675b71c13 ]--- With KASAN also enabled, we may also get many use-after-free reports. The issue is that when CONFIG_DEBUG_TEST_DRIVER_REMOVE is set, we may attempt to detach the ata_port before it has been probed. This is because the ata_ports are async probed, meaning that there is no guarantee that the ata_port has probed prior to detach. When the ata_port does probe in this scenario, we get all sorts of issues as the detach may have already happened. Fix by ensuring synchronisation with async_synchronize_full(). We could alternatively use the cookie returned from the ata_port probe async_schedule() call, but that means managing the cookie, so more complicated. Signed-off-by: John Garry Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/ata/libata-core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index da1a987c622a4..b1582f1611717 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -6550,6 +6550,9 @@ void ata_host_detach(struct ata_host *host) { int i; + /* Ensure ata_port probe has completed */ + async_synchronize_full(); + for (i = 0; i < host->n_ports; i++) ata_port_detach(host->ports[i]); -- 2.20.1