From patchwork Thu Oct 24 16:45:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Keeping X-Patchwork-Id: 11210395 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 69850112C for ; Thu, 24 Oct 2019 17:05:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E97321D7E for ; Thu, 24 Oct 2019 17:05:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=metanate.com header.i=@metanate.com header.b="CrpDtFtR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2410064AbfJXRFI (ORCPT ); Thu, 24 Oct 2019 13:05:08 -0400 Received: from dougal.metanate.com ([90.155.101.14]:4724 "EHLO metanate.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2405819AbfJXRFI (ORCPT ); Thu, 24 Oct 2019 13:05:08 -0400 X-Greylist: delayed 1158 seconds by postgrey-1.27 at vger.kernel.org; Thu, 24 Oct 2019 13:05:07 EDT DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=simple/simple; d=metanate.com; s=stronger; h=Content-Transfer-Encoding:MIME-Version:Message-Id:Date:Subject :Cc:To:From:Sender:Reply-To:Content-Type:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=VPmIoUH0glx+4sENj5EpAXnVlu8h+LV7UwdHblVC1Ng=; b=CrpDtFtRqbksIhycdO0lgzURu+ 8yjQ5E8VqRi22Exu5Z2OryrkD5BvTXOSvzoz5/VbTwGdOgtVFTe9EAO+XmJzVsJBtK+GCJXPeOU8q JyW0P1mrrB39R/NO9aMAtuo7mHixa6/7kK6fenK3uGHOmx2BVccR8YjDuMrJgR2gy3C4HdJBOJN7O bHQbvWOaAo3M47xf7okxFiQLebFekLLDQp4Aq+xpr+YCkOGmwaZqm06/gwsZUPcJBuE/tOGaSRg3v 1ATaMjAG7/apiZ+TlttBvy7uurNgYfL/bvG96VNt99pYkDC0gQVuP9xYLl92jtbbWV9kBIzR2UUY+ p6bp7lHg==; Received: from 188-39-28-98.static.enta.net ([188.39.28.98] helo=donbot.corp.numark.com) by email.metanate.com with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92.3) (envelope-from ) id 1iNgF9-0004oc-4a; Thu, 24 Oct 2019 17:45:47 +0100 From: John Keeping To: linux-usb@vger.kernel.org Cc: Felipe Balbi , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, John Keeping Subject: [PATCH 0/6] USB: gadget: f_hid: fix lifetime issues Date: Thu, 24 Oct 2019 17:45:32 +0100 Message-Id: <20191024164538.3161474-1-john@metanate.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 X-Authenticated: YES Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org File descriptors referencing the /dev/hidgN device created by the HID gadget can outlive the underlying gadget function, which creates easy to trigger use-after-frees in the kernel. A simple reproduction for this using the libusbgx example programs is: $ gadget-hid $ exec 3<> /dev/hidg0 $ gadget-vid-pid-remove $ exec 3<&- Closing the file descriptor on the last line triggers a use-after-free which can be seen immediately with slub_debug=P. This series fixes this by making the struct cdev associated with the module rather than dynamically allocated for the gadget and changing struct f_hidg to be refcounted instead of tied to the gadget lifetime. John Keeping (6): USB: gadget: f_hid: move chardev setup to module init USB: gadget: f_hid: switch to IDR for tracking minors USB: gadget: f_hid: find f_hidg by IDR lookup on open USB: gadget: f_hid: decouple cdev from f_hidg lifetime USB: gadget: f_hid: refcount f_hidg structure USB: gadget: f_hid: return ENODEV from read/write after deletion drivers/usb/gadget/function/f_hid.c | 141 +++++++++++++++++++--------- drivers/usb/gadget/function/u_hid.h | 3 - 2 files changed, 95 insertions(+), 49 deletions(-)