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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 ECBDCC2BA83 for ; Wed, 12 Feb 2020 13:47:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B5E3B20724 for ; Wed, 12 Feb 2020 13:47:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581515256; bh=ro3LSlOyjGaCnmdhkZyiUrM+ZZXKFjz46uFU39iMKSc=; h=Date:From:To:cc:Subject:In-Reply-To:References:List-ID:From; b=NaHGpGPihMn3AlTCu96Dz7vvJBjNYYbcGqwznO3IIQi49hG6fuPD4WryJh9oOds9u CVqyES2Zbe1HDsX6P0PoY1AVowT09zxYmTos9zgW8zcFPgyR72GnGNnIna5ODlnqQR /EJjixmsyJ0RL6KMZeFfmqyQTBy1ehDMeM4NtclQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728080AbgBLNrg (ORCPT ); Wed, 12 Feb 2020 08:47:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:40602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727439AbgBLNrf (ORCPT ); Wed, 12 Feb 2020 08:47:35 -0500 Received: from pobox.suse.cz (prg-ext-pat.suse.com [213.151.95.130]) (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 9508C206B6; Wed, 12 Feb 2020 13:47:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581515255; bh=ro3LSlOyjGaCnmdhkZyiUrM+ZZXKFjz46uFU39iMKSc=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=sz2rx/U/NGWhMakQft6YyTpSCHRYBu+NylRYYK0/D4m6mbpHGa/ErjQsUwaSaFst6 n0SFofDSuom4AsQlEdekNhRhS/SQiy/1l87CSIy24mgfnNH8r0GObHfjIfokCZxOED oWN1TZab3PAer0lf88toG1SWinsmGcu6X/fNUu2M= Date: Wed, 12 Feb 2020 14:47:31 +0100 (CET) From: Jiri Kosina To: Dan Carpenter , syzbot cc: Alan Stern , andreyknvl@google.com, syzkaller-bugs@googlegroups.com, Benjamin Tissoires , linux-usb@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] HID: hiddev: Fix race in in hiddev_disconnect() In-Reply-To: <20200115174628.zxpxbpa6bwspjajg@kili.mountain> Message-ID: References: <20200115174628.zxpxbpa6bwspjajg@kili.mountain> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 15 Jan 2020, Dan Carpenter wrote: > 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 Applied to for-5.6/upstream-fixes. Thanks, -- Jiri Kosina SUSE Labs