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=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no 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 E51BBC4338F for ; Fri, 23 Jul 2021 16:48:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C645E60E73 for ; Fri, 23 Jul 2021 16:48:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230393AbhGWQIQ (ORCPT ); Fri, 23 Jul 2021 12:08:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229847AbhGWQIQ (ORCPT ); Fri, 23 Jul 2021 12:08:16 -0400 Received: from mail-lf1-x129.google.com (mail-lf1-x129.google.com [IPv6:2a00:1450:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1365FC061575 for ; Fri, 23 Jul 2021 09:48:48 -0700 (PDT) Received: by mail-lf1-x129.google.com with SMTP id bp1so3121270lfb.3 for ; Fri, 23 Jul 2021 09:48:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=91aQFRYIdgzj88IJSIkdm28VlazqEvs9hYL7HHJxDXk=; b=XW/m8ZN3fwu7Z5pQmde3f5jvv+IYVT+DJenurWjN3gEVVTMavo99HL3vhP00ldDJr3 563xPFcq1zcftiqyIOuQUhh6vA8KztVGbmvUgXCo6yZLmYvlS2nTlMWZeUxzui33Kb0y EdZQGBj+EkRIMzPbDO9GtxGxsjh9z/7wvW17kDPMgNgY33LsoHdG0OsIHJS5ZXdI5wq3 mEtJGfiJB9g1hFVOpzTQjVRRImm9HegeDWlVlM1Egb9f+LZ+yIad79x9uIFfYFAj4FQu Lr3pZ4deHxUJVNeI2RdoOnZoxb1PHjDrWkIIuHk7kPMFH2yY7ZJmqOy+XCUrYlftGrm1 VoIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=91aQFRYIdgzj88IJSIkdm28VlazqEvs9hYL7HHJxDXk=; b=EnE9BEHZRYyNhdbu6w5t48O478YIvLKNF7Vxz2CjiHdMVkPerkiHZCTNMiUY+jGPJ5 JZoPT6S4nv/A6ykU1gqfU6M2AnxY+5jYqPMieKMl1qvTtzWg76VZoCtycSquuVBmPPYW /5yaZ/uQ0jPP1P+/7u+dS+liJylhZO+CH58y283KlZ5yfB/hFPouRxHhEL/lX9s+mS5z fzNdc+lcZcPNVYYwM87gxAcWHfiwGivEESc0wVi4ZId0Dlv7u0HQPYXTMyBY05YjgljG Cn6FakbiQ8AEhLpmjgfhBAVqq3ufj5aVQ+eCs+4ivpQG2n32RfpFzxmvslxcK8lUsHFl nnYw== X-Gm-Message-State: AOAM530NmJ4ceEFrZDdsc23xl/G7C3FNeTh03Iz0W1LWWScffWJ1cCks K4YmQstNy06hA+LtmV+75/E= X-Google-Smtp-Source: ABdhPJwO/3aTGxNI+VpLl+syvq2OFoKeamRtTn5rfck2WL2Akc+T5fmfJvuW/fKzaV5xFwSnV/tQng== X-Received: by 2002:a05:6512:3458:: with SMTP id j24mr3702359lfr.366.1627058926397; Fri, 23 Jul 2021 09:48:46 -0700 (PDT) Received: from reki (broadband-95-84-198-152.ip.moscow.rt.ru. [95.84.198.152]) by smtp.gmail.com with ESMTPSA id f23sm116430lfc.225.2021.07.23.09.48.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Jul 2021 09:48:46 -0700 (PDT) Date: Fri, 23 Jul 2021 19:48:44 +0300 From: Maxim Devaev To: Greg KH Cc: balbi@kernel.org, sandeen@redhat.com, linux-usb@vger.kernel.org, Phil Elwell Subject: Re: [PATCH v2] usb: gadget: f_hid: fixed NULL pointer dereference Message-ID: <20210723194844.54773693@reki> In-Reply-To: References: <20210723155928.210019-1-mdevaev@gmail.com> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org > > + if (!hidg->in_ep->enabled) { > > + ERROR(hidg->func.config->cdev, "in_ep is disabled\n"); > > + status = -ESHUTDOWN; > > + goto release_write_pending; > > What prevents "enabled" from changing right after you test this? You do > not have the lock held so could it change then? Inside usb_ep_queue() a similar check is used without blocking. I suppose this is how it should be. Here it's necessary for the error message. > > + } > > + > > status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC); > > - if (status < 0) { > > - ERROR(hidg->func.config->cdev, > > - "usb_ep_queue error on int endpoint %zd\n", status); > > + if (status < 0) > > goto release_write_pending; > > No error message if queueing up failed? Yes. For each write from userspace, this generates one message. This can lead to a huge spam in the log.