From patchwork Tue Mar 10 12:38:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229467 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=unavailable 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 28C08C10F27 for ; Tue, 10 Mar 2020 13:34:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EDE5F20675 for ; Tue, 10 Mar 2020 13:34:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583847274; bh=k+hGJZYSyfR7ivL/m9ThcSWN/LBHQZfZdVkxeHyYmkE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=bdouYKvYY+AYGynOgsPIvfdaA/SNWvpX55vBE/4EkbLjz8PNiXrneJJq/pt1T7Atr DkMAVYeqSWPvYYLx+GMhvuGXsW8EDKVI1McPccmQBqk5yp8FXSMOr9SRTaEdqlpc2D P8K3G5PPC+aSGAeyLIdi8nJK62K2KS0DY0qLAAw4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728022AbgCJMqd (ORCPT ); Tue, 10 Mar 2020 08:46:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:49624 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727821AbgCJMqY (ORCPT ); Tue, 10 Mar 2020 08:46:24 -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 598A02467D; Tue, 10 Mar 2020 12:46:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583844383; bh=k+hGJZYSyfR7ivL/m9ThcSWN/LBHQZfZdVkxeHyYmkE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JBpNMpWHYySXFMFjv3vCJzRlBS8+nxFiwzlLsj3DpZnpZSeXJlgkWyp+oiP9a2Lzk /sEwvJGKGU3CZ8xn7H3Ms252MuvmmJGRHG9bAynQQ5xUKo+8M2WDl55A7tf35CNZJb Cah04Tm0rncmQkki7i1OYiZnjjmUziFFb3XADWto= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+784ccb935f9900cc7c9e@syzkaller.appspotmail.com, Alan Stern , Dan Carpenter , Jiri Kosina Subject: [PATCH 4.9 34/88] HID: hiddev: Fix race in in hiddev_disconnect() Date: Tue, 10 Mar 2020 13:38:42 +0100 Message-Id: <20200310123614.195198369@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200310123606.543939933@linuxfoundation.org> References: <20200310123606.543939933@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: dan.carpenter@oracle.com commit 5c02c447eaeda29d3da121a2e17b97ccaf579b51 upstream. Syzbot reports that "hiddev" is used after it's free in hiddev_disconnect(). The hiddev_disconnect() function sets "hiddev->exist = 0;" so hiddev_release() can free it as soon as we drop the "existancelock" lock. This patch moves the mutex_unlock(&hiddev->existancelock) until after we have finished using it. Reported-by: syzbot+784ccb935f9900cc7c9e@syzkaller.appspotmail.com Fixes: 7f77897ef2b6 ("HID: hiddev: fix potential use-after-free") Suggested-by: Alan Stern Signed-off-by: Dan Carpenter Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/usbhid/hiddev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -962,9 +962,9 @@ void hiddev_disconnect(struct hid_device hiddev->exist = 0; if (hiddev->open) { - mutex_unlock(&hiddev->existancelock); usbhid_close(hiddev->hid); wake_up_interruptible(&hiddev->wait); + mutex_unlock(&hiddev->existancelock); } else { mutex_unlock(&hiddev->existancelock); kfree(hiddev);