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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 A97F1FA3728 for ; Wed, 16 Oct 2019 21:55:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81E4E21928 for ; Wed, 16 Oct 2019 21:55:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571262956; bh=B0dcqoSbicMHkVqB5HcqhintxRZrIi1P7Pzde2xZLLc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RMOFgEmCpetzIxyYURal8VnoK4jQOoLnor2dhj9bIXuWXBoRX8JCYH1r2aFc4j1pG WzbR9WIjq1Reex+Jp+RRETvFcZUPBCSJnilN4cYY3KPSHNDkN+3F3onQDbNgHRU6Pd B9Xn0xVIrirbLbWJSqIzdX//cHmu4Dux5x7Ew29I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437849AbfJPVzz (ORCPT ); Wed, 16 Oct 2019 17:55:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:46976 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437838AbfJPVzx (ORCPT ); Wed, 16 Oct 2019 17:55:53 -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 27C1621925; Wed, 16 Oct 2019 21:55:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571262952; bh=B0dcqoSbicMHkVqB5HcqhintxRZrIi1P7Pzde2xZLLc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FxAmalAQLSuQaQcShACg807qlXlHt6dRG8fj9Z+ssqd0WkhPWfyI15fpLpJhgcgN7 lL5rLj9cHL1kPs/E7fx5LYIaW+ngYaif8gOK8HByBD3zcv+5Tx2REmF3MYwyB/2+4T /Vq1LWFLEmBdCjeTNMjUMni9MHlX/+YmNUMSM2aA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johan Hovold Subject: [PATCH 4.14 22/65] USB: ldusb: fix NULL-derefs on driver unbind Date: Wed, 16 Oct 2019 14:50:36 -0700 Message-Id: <20191016214818.168238921@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191016214756.457746573@linuxfoundation.org> References: <20191016214756.457746573@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 58ecf131e74620305175a7aa103f81350bb37570 upstream. The driver was using its struct usb_interface pointer as an inverted disconnected flag, but was setting it to NULL before making sure all completion handlers had run. This could lead to a NULL-pointer dereference in a number of dev_dbg, dev_warn and dev_err statements in the completion handlers which relies on said pointer. Fix this by unconditionally stopping all I/O and preventing resubmissions by poisoning the interrupt URBs at disconnect and using a dedicated disconnected flag. This also makes sure that all I/O has completed by the time the disconnect callback returns. Fixes: 2824bd250f0b ("[PATCH] USB: add ldusb driver") Cc: stable # 2.6.13 Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20191009153848.8664-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/ldusb.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) --- a/drivers/usb/misc/ldusb.c +++ b/drivers/usb/misc/ldusb.c @@ -157,6 +157,7 @@ MODULE_PARM_DESC(min_interrupt_out_inter struct ld_usb { struct mutex mutex; /* locks this structure */ struct usb_interface *intf; /* save off the usb interface pointer */ + unsigned long disconnected:1; int open_count; /* number of times this port has been opened */ @@ -196,12 +197,10 @@ static void ld_usb_abort_transfers(struc /* shutdown transfer */ if (dev->interrupt_in_running) { dev->interrupt_in_running = 0; - if (dev->intf) - usb_kill_urb(dev->interrupt_in_urb); + usb_kill_urb(dev->interrupt_in_urb); } if (dev->interrupt_out_busy) - if (dev->intf) - usb_kill_urb(dev->interrupt_out_urb); + usb_kill_urb(dev->interrupt_out_urb); } /** @@ -209,8 +208,6 @@ static void ld_usb_abort_transfers(struc */ static void ld_usb_delete(struct ld_usb *dev) { - ld_usb_abort_transfers(dev); - /* free data structures */ usb_free_urb(dev->interrupt_in_urb); usb_free_urb(dev->interrupt_out_urb); @@ -266,7 +263,7 @@ static void ld_usb_interrupt_in_callback resubmit: /* resubmit if we're still running */ - if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) { + if (dev->interrupt_in_running && !dev->buffer_overflow) { retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC); if (retval) { dev_err(&dev->intf->dev, @@ -395,7 +392,7 @@ static int ld_usb_release(struct inode * retval = -ENODEV; goto unlock_exit; } - if (dev->intf == NULL) { + if (dev->disconnected) { /* the device was unplugged before the file was released */ mutex_unlock(&dev->mutex); /* unlock here as ld_usb_delete frees dev */ @@ -426,7 +423,7 @@ static unsigned int ld_usb_poll(struct f dev = file->private_data; - if (!dev->intf) + if (dev->disconnected) return POLLERR | POLLHUP; poll_wait(file, &dev->read_wait, wait); @@ -465,7 +462,7 @@ static ssize_t ld_usb_read(struct file * } /* verify that the device wasn't unplugged */ - if (dev->intf == NULL) { + if (dev->disconnected) { retval = -ENODEV; printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval); goto unlock_exit; @@ -545,7 +542,7 @@ static ssize_t ld_usb_write(struct file } /* verify that the device wasn't unplugged */ - if (dev->intf == NULL) { + if (dev->disconnected) { retval = -ENODEV; printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval); goto unlock_exit; @@ -762,6 +759,9 @@ static void ld_usb_disconnect(struct usb /* give back our minor */ usb_deregister_dev(intf, &ld_usb_class); + usb_poison_urb(dev->interrupt_in_urb); + usb_poison_urb(dev->interrupt_out_urb); + mutex_lock(&dev->mutex); /* if the device is not opened, then we clean up right now */ @@ -769,7 +769,7 @@ static void ld_usb_disconnect(struct usb mutex_unlock(&dev->mutex); ld_usb_delete(dev); } else { - dev->intf = NULL; + dev->disconnected = 1; /* wake up pollers */ wake_up_interruptible_all(&dev->read_wait); wake_up_interruptible_all(&dev->write_wait);