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,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 25446C3F2C6 for ; Tue, 3 Mar 2020 18:11:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0162820656 for ; Tue, 3 Mar 2020 18:11:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583259066; bh=VGDXLgoKIE7Lop4XztxaT7+DKnqNk4iOdpGwTxrGzKI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dIqfl4FRqEmlvfHa+bGX+AohyNRp7WeQ4jx9g520kAWBsIkDGnuNhPNHLJePzbmQJ DLypG4E5VBDKO09woEau3HnkMCuax/dXx8eigAJ5HaGHhSjPplwtpXCLxMU+kVYNvx PefPTSoH5kCrltlM+inRHJlVogXhgE9pNPQhgDm8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387880AbgCCSLE (ORCPT ); Tue, 3 Mar 2020 13:11:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:57736 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731860AbgCCRuK (ORCPT ); Tue, 3 Mar 2020 12:50:10 -0500 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 F217520870; Tue, 3 Mar 2020 17:50:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583257809; bh=VGDXLgoKIE7Lop4XztxaT7+DKnqNk4iOdpGwTxrGzKI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aPK61MkGcbRl6Lkm1MJrxBOHFWlIS+yLrRSuW7HEglkHfLtAFt8tOWllrP6la81VD X7y/QOBqlRYlaHAbLCgoRKqEQLeaHuMPsHmNcuYM5gbsmPfV8j9WH/FhgZnSXgB3iT V/WcKuJpTEk21bchArgsHD0cnoyADFjObWcPIom8= 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 5.5 108/176] HID: hiddev: Fix race in in hiddev_disconnect() Date: Tue, 3 Mar 2020 18:42:52 +0100 Message-Id: <20200303174317.336973355@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174304.593872177@linuxfoundation.org> References: <20200303174304.593872177@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: 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 @@ -932,9 +932,9 @@ void hiddev_disconnect(struct hid_device hiddev->exist = 0; if (hiddev->open) { - mutex_unlock(&hiddev->existancelock); hid_hw_close(hiddev->hid); wake_up_interruptible(&hiddev->wait); + mutex_unlock(&hiddev->existancelock); } else { mutex_unlock(&hiddev->existancelock); kfree(hiddev);