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=-6.9 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,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 25CD8C2D0F9 for ; Wed, 13 May 2020 09:51:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F11E623127 for ; Wed, 13 May 2020 09:51:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589363465; bh=+KCU1v8AF1ldibfn5M/2mbw8+9wD9iUOtgyk2tciFyM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JAbKetbzQ0MSG3z/iCaRgBppSRJn8JA8OKMhF/cebvK+LyF1J7ZjkebSRPH80OiWG kwuW07RuwPCAA0JEiNcznp9DsDNwAJELqA3YIDY5tyX3aeYMMJc+Hd3zdaxthcgooq zqbohe9LOZTAYegql/lf0l7SREL4pGFAk2DRj1ec= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387598AbgEMJvE (ORCPT ); Wed, 13 May 2020 05:51:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:51350 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387582AbgEMJvB (ORCPT ); Wed, 13 May 2020 05:51:01 -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 BC58C20575; Wed, 13 May 2020 09:50:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589363460; bh=+KCU1v8AF1ldibfn5M/2mbw8+9wD9iUOtgyk2tciFyM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nKBIrn2dpt/Cuq02bdy4WLN0WRL1wiqTRND251kfRgLe2G3wCx3ANJ5B9vXsQGCDX XMCwzk5Ei5etrQc78ppQehpIYrvswpyIn+/koYNgZi/izbU3usPuP4RXUPZ+Wa5phF GX/YAL1eehako6gHRIwbWFphoGFyBq72MS85Xygw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Stern , Jiri Kosina , syzbot+7bf5a7b0f0a1f9446f4c@syzkaller.appspotmail.com Subject: [PATCH 5.4 44/90] HID: usbhid: Fix race between usbhid_close() and usbhid_stop() Date: Wed, 13 May 2020 11:44:40 +0200 Message-Id: <20200513094413.466529428@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200513094408.810028856@linuxfoundation.org> References: <20200513094408.810028856@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: Alan Stern commit 0ed08faded1da03eb3def61502b27f81aef2e615 upstream. The syzbot fuzzer discovered a bad race between in the usbhid driver between usbhid_stop() and usbhid_close(). In particular, usbhid_stop() does: usb_free_urb(usbhid->urbin); ... usbhid->urbin = NULL; /* don't mess up next start */ and usbhid_close() does: usb_kill_urb(usbhid->urbin); with no mutual exclusion. If the two routines happen to run concurrently so that usb_kill_urb() is called in between the usb_free_urb() and the NULL assignment, it will access the deallocated urb structure -- a use-after-free bug. This patch adds a mutex to the usbhid private structure and uses it to enforce mutual exclusion of the usbhid_start(), usbhid_stop(), usbhid_open() and usbhid_close() callbacks. Reported-and-tested-by: syzbot+7bf5a7b0f0a1f9446f4c@syzkaller.appspotmail.com Signed-off-by: Alan Stern CC: Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/usbhid/hid-core.c | 37 +++++++++++++++++++++++++++++-------- drivers/hid/usbhid/usbhid.h | 1 + 2 files changed, 30 insertions(+), 8 deletions(-) --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -682,16 +682,21 @@ static int usbhid_open(struct hid_device struct usbhid_device *usbhid = hid->driver_data; int res; + mutex_lock(&usbhid->mutex); + set_bit(HID_OPENED, &usbhid->iofl); - if (hid->quirks & HID_QUIRK_ALWAYS_POLL) - return 0; + if (hid->quirks & HID_QUIRK_ALWAYS_POLL) { + res = 0; + goto Done; + } res = usb_autopm_get_interface(usbhid->intf); /* the device must be awake to reliably request remote wakeup */ if (res < 0) { clear_bit(HID_OPENED, &usbhid->iofl); - return -EIO; + res = -EIO; + goto Done; } usbhid->intf->needs_remote_wakeup = 1; @@ -725,6 +730,9 @@ static int usbhid_open(struct hid_device msleep(50); clear_bit(HID_RESUME_RUNNING, &usbhid->iofl); + + Done: + mutex_unlock(&usbhid->mutex); return res; } @@ -732,6 +740,8 @@ static void usbhid_close(struct hid_devi { struct usbhid_device *usbhid = hid->driver_data; + mutex_lock(&usbhid->mutex); + /* * Make sure we don't restart data acquisition due to * a resumption we no longer care about by avoiding racing @@ -743,12 +753,13 @@ static void usbhid_close(struct hid_devi clear_bit(HID_IN_POLLING, &usbhid->iofl); spin_unlock_irq(&usbhid->lock); - if (hid->quirks & HID_QUIRK_ALWAYS_POLL) - return; + if (!(hid->quirks & HID_QUIRK_ALWAYS_POLL)) { + hid_cancel_delayed_stuff(usbhid); + usb_kill_urb(usbhid->urbin); + usbhid->intf->needs_remote_wakeup = 0; + } - hid_cancel_delayed_stuff(usbhid); - usb_kill_urb(usbhid->urbin); - usbhid->intf->needs_remote_wakeup = 0; + mutex_unlock(&usbhid->mutex); } /* @@ -1057,6 +1068,8 @@ static int usbhid_start(struct hid_devic unsigned int n, insize = 0; int ret; + mutex_lock(&usbhid->mutex); + clear_bit(HID_DISCONNECTED, &usbhid->iofl); usbhid->bufsize = HID_MIN_BUFFER_SIZE; @@ -1177,6 +1190,8 @@ static int usbhid_start(struct hid_devic usbhid_set_leds(hid); device_set_wakeup_enable(&dev->dev, 1); } + + mutex_unlock(&usbhid->mutex); return 0; fail: @@ -1187,6 +1202,7 @@ fail: usbhid->urbout = NULL; usbhid->urbctrl = NULL; hid_free_buffers(dev, hid); + mutex_unlock(&usbhid->mutex); return ret; } @@ -1202,6 +1218,8 @@ static void usbhid_stop(struct hid_devic usbhid->intf->needs_remote_wakeup = 0; } + mutex_lock(&usbhid->mutex); + clear_bit(HID_STARTED, &usbhid->iofl); spin_lock_irq(&usbhid->lock); /* Sync with error and led handlers */ set_bit(HID_DISCONNECTED, &usbhid->iofl); @@ -1222,6 +1240,8 @@ static void usbhid_stop(struct hid_devic usbhid->urbout = NULL; hid_free_buffers(hid_to_usb_dev(hid), hid); + + mutex_unlock(&usbhid->mutex); } static int usbhid_power(struct hid_device *hid, int lvl) @@ -1382,6 +1402,7 @@ static int usbhid_probe(struct usb_inter INIT_WORK(&usbhid->reset_work, hid_reset); timer_setup(&usbhid->io_retry, hid_retry_timeout, 0); spin_lock_init(&usbhid->lock); + mutex_init(&usbhid->mutex); ret = hid_add_device(hid); if (ret) { --- a/drivers/hid/usbhid/usbhid.h +++ b/drivers/hid/usbhid/usbhid.h @@ -80,6 +80,7 @@ struct usbhid_device { dma_addr_t outbuf_dma; /* Output buffer dma */ unsigned long last_out; /* record of last output for timeouts */ + struct mutex mutex; /* start/stop/open/close */ spinlock_t lock; /* fifo spinlock */ unsigned long iofl; /* I/O flags (CTRL_RUNNING, OUT_RUNNING) */ struct timer_list io_retry; /* Retry timer */