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,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 0CE4CC3A5A3 for ; Thu, 22 Aug 2019 17:10:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D48D52089E for ; Thu, 22 Aug 2019 17:10:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566493847; bh=nIjJKHeNEvGgEnQO4HTGcN074YQkaMe++jyaTSfgJXc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kNlwZJZmo1sMdUIVOubtgk3XjRcZ8NkLfLO7C5ugDTLxN1gfgOfIyPQSL51mT1jEj xFH5wUbxXOQpla4cZ+DXQVBYKtlQYKAtN8By/RgoCXm10CAPl4rftYXuEuXxO0IZtT ztSbJgAlVsNjrkOeGGsjTGACj6cF9zDIjvAmtrP0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390744AbfHVRJV (ORCPT ); Thu, 22 Aug 2019 13:09:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:59350 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390673AbfHVRJI (ORCPT ); Thu, 22 Aug 2019 13:09:08 -0400 Received: from sasha-vm.mshome.net (wsip-184-188-36-2.sd.sd.cox.net [184.188.36.2]) (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 074F223406; Thu, 22 Aug 2019 17:09:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566493747; bh=nIjJKHeNEvGgEnQO4HTGcN074YQkaMe++jyaTSfgJXc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wjkXBp3E+YxgSFPk+ossmyx9sTQIG7G3dudAn2RWtpWvriCd3EzdC0pJdEn7RdN8D NAPkiRNY3Oad/+Zx2ifWnpkBmhGqegMF/5YLeEZ+2Ml/H/OsbE5koGfpiI2sOFHlHi NOGPQTQpKgleljoj1EmlA4mqwfLIRoxGPnb2BvL0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oliver Neukum , syzbot+1b2449b7b5dc240d107a@syzkaller.appspotmail.com, Greg Kroah-Hartman Subject: [PATCH 5.2 097/135] usb: cdc-acm: make sure a refcount is taken early enough Date: Thu, 22 Aug 2019 13:07:33 -0400 Message-Id: <20190822170811.13303-98-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190822170811.13303-1-sashal@kernel.org> References: <20190822170811.13303-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.2.10-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.2.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.2.10-rc1 X-KernelTest-Deadline: 2019-08-24T17:07+00:00 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: Oliver Neukum commit c52873e5a1ef72f845526d9f6a50704433f9c625 upstream. destroy() will decrement the refcount on the interface, so that it needs to be taken so early that it never undercounts. Fixes: 7fb57a019f94e ("USB: cdc-acm: Fix potential deadlock (lockdep warning)") Cc: stable Reported-and-tested-by: syzbot+1b2449b7b5dc240d107a@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum Link: https://lore.kernel.org/r/20190808142119.7998-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 183b41753c982..62f4fb9b362f1 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1301,10 +1301,6 @@ static int acm_probe(struct usb_interface *intf, tty_port_init(&acm->port); acm->port.ops = &acm_port_ops; - minor = acm_alloc_minor(acm); - if (minor < 0) - goto alloc_fail1; - ctrlsize = usb_endpoint_maxp(epctrl); readsize = usb_endpoint_maxp(epread) * (quirks == SINGLE_RX_URB ? 1 : 2); @@ -1312,6 +1308,13 @@ static int acm_probe(struct usb_interface *intf, acm->writesize = usb_endpoint_maxp(epwrite) * 20; acm->control = control_interface; acm->data = data_interface; + + usb_get_intf(acm->control); /* undone in destruct() */ + + minor = acm_alloc_minor(acm); + if (minor < 0) + goto alloc_fail1; + acm->minor = minor; acm->dev = usb_dev; if (h.usb_cdc_acm_descriptor) @@ -1458,7 +1461,6 @@ static int acm_probe(struct usb_interface *intf, usb_driver_claim_interface(&acm_driver, data_interface, acm); usb_set_intfdata(data_interface, acm); - usb_get_intf(control_interface); tty_dev = tty_port_register_device(&acm->port, acm_tty_driver, minor, &control_interface->dev); if (IS_ERR(tty_dev)) { -- 2.20.1