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[209.132.180.67]) by mx.google.com with ESMTP id j47si2998573ede.117.2019.10.17.22.00.47; Thu, 17 Oct 2019 22:01:10 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=otcNFN26; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389966AbfJPWR7 (ORCPT + 99 others); Wed, 16 Oct 2019 18:17:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:44638 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437713AbfJPVyi (ORCPT ); Wed, 16 Oct 2019 17:54:38 -0400 Received: from localhost (unknown [192.55.54.58]) (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 282E421A4C; Wed, 16 Oct 2019 21:54:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571262876; bh=rfASr3IKubPje+T8VgFF+tS3jyFedjIoi1VksgpQP8w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=otcNFN26lcutWUbKy49Hfk2XodixNz3pKXwFU1Mf4usNPr0q9dBN6IrkzfwbfuAqH mvT115tMwkBRIbE2tySGX5xtVK9ErN89u4rbdehX3Z0fn2VaqCoEP43X6jhL3EH4P+ R1Plq6zp4CP64/DrF+iSz4qhz0YuRifoWUwi07Ho= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johan Hovold Subject: [PATCH 4.9 39/92] USB: yurex: fix NULL-derefs on disconnect Date: Wed, 16 Oct 2019 14:50:12 -0700 Message-Id: <20191016214829.782371694@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191016214759.600329427@linuxfoundation.org> References: <20191016214759.600329427@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: Johan Hovold commit aafb00a977cf7d81821f7c9d12e04c558c22dc3c upstream. The driver was using its struct usb_interface pointer as an inverted disconnected flag, but was setting it to NULL without making sure all code paths that used it were done with it. Before commit ef61eb43ada6 ("USB: yurex: Fix protection fault after device removal") this included the interrupt-in completion handler, but there are further accesses in dev_err and dev_dbg statements in yurex_write() and the driver-data destructor (sic!). Fix this by unconditionally stopping also the control URB at disconnect and by using a dedicated disconnected flag. Note that we need to take a reference to the struct usb_interface to avoid a use-after-free in the destructor whenever the device was disconnected while the character device was still open. Fixes: aadd6472d904 ("USB: yurex.c: remove dbg() usage") Fixes: 45714104b9e8 ("USB: yurex.c: remove err() usage") Cc: stable # 3.5: ef61eb43ada6 Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20191009153848.8664-6-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/yurex.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/drivers/usb/misc/yurex.c +++ b/drivers/usb/misc/yurex.c @@ -64,6 +64,7 @@ struct usb_yurex { struct kref kref; struct mutex io_mutex; + unsigned long disconnected:1; struct fasync_struct *async_queue; wait_queue_head_t waitq; @@ -111,6 +112,7 @@ static void yurex_delete(struct kref *kr dev->int_buffer, dev->urb->transfer_dma); usb_free_urb(dev->urb); } + usb_put_intf(dev->interface); usb_put_dev(dev->udev); kfree(dev); } @@ -209,7 +211,7 @@ static int yurex_probe(struct usb_interf init_waitqueue_head(&dev->waitq); dev->udev = usb_get_dev(interface_to_usbdev(interface)); - dev->interface = interface; + dev->interface = usb_get_intf(interface); /* set up the endpoint information */ iface_desc = interface->cur_altsetting; @@ -326,8 +328,9 @@ static void yurex_disconnect(struct usb_ /* prevent more I/O from starting */ usb_poison_urb(dev->urb); + usb_poison_urb(dev->cntl_urb); mutex_lock(&dev->io_mutex); - dev->interface = NULL; + dev->disconnected = 1; mutex_unlock(&dev->io_mutex); /* wakeup waiters */ @@ -415,7 +418,7 @@ static ssize_t yurex_read(struct file *f dev = file->private_data; mutex_lock(&dev->io_mutex); - if (!dev->interface) { /* already disconnected */ + if (dev->disconnected) { /* already disconnected */ mutex_unlock(&dev->io_mutex); return -ENODEV; } @@ -450,7 +453,7 @@ static ssize_t yurex_write(struct file * goto error; mutex_lock(&dev->io_mutex); - if (!dev->interface) { /* already disconnected */ + if (dev->disconnected) { /* already disconnected */ mutex_unlock(&dev->io_mutex); retval = -ENODEV; goto error;