From patchwork Tue Dec 7 17:43:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 522462 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01641C433EF for ; Tue, 7 Dec 2021 17:44:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240144AbhLGRrh (ORCPT ); Tue, 7 Dec 2021 12:47:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235293AbhLGRrg (ORCPT ); Tue, 7 Dec 2021 12:47:36 -0500 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86BB2C061746 for ; Tue, 7 Dec 2021 09:44:06 -0800 (PST) Received: by mail-pl1-x636.google.com with SMTP id u17so9950941plg.9 for ; Tue, 07 Dec 2021 09:44:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=bKVPunnAxyXz+rHlZKIN2IVzism2juiwgT6PKshCozU=; b=g08A0M2bPh+rgy8MOJtpx32VGr1fMqLdHLNLt6aSdjaPt15hbIcTQFk/bW4I3pLqq6 3bncPVm4iyI579KugmfCswYGs3j/OsFo6Z7aT/IPaE/DN2mciknvfG/p5lcVESiKOPc5 vdQKnIIWxJtTYmUaUoxBERd33b+vCDz6aBk+Q= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=bKVPunnAxyXz+rHlZKIN2IVzism2juiwgT6PKshCozU=; b=Iy0f6K1c2pl3Xjp4SwWikqUlAKHm/AKB4QHNCkscTkYoOuaelR3PPlJQcdOFArT8Zy uksVDpYq9wHQm+oC/6owJ9zQmdvkFipcIPboAWgUoFNZeJaXImt5Kb9MPIykblxWepoi rFATwjTLjF3S0amnDHSDYjxYoFaau68Rh1+JPIFjr0oqDQ9GmKce8kJs9ZQhuPRaYefn zT7QaDCGdae86Xny9Wg3SgupL1NEK1hvlv+E/oh9cxyHLZDtk9Jd92tGDXUPNhPNyQpb h2FalN0AHVMX0vOJ9yi4B8zD62HcUOPVKe14W87n85LBbSyFy3+Qq594H//fHcPL9z6N 0/jw== X-Gm-Message-State: AOAM533VR70yinAONPiQuzn006uPsYvww52wcaXv8kYbtZLJNN4lyuvk AFC0bPU5OJZYzeD+CDjYN+QzFA== X-Google-Smtp-Source: ABdhPJxJ31RcYOHwb6V87S7NxBD3mUEpOroWbvBAHYX1ZOU7pjTezVaWt/LZIWNtR5BxxWkOMrCVBA== X-Received: by 2002:a17:90a:1b63:: with SMTP id q90mr567550pjq.126.1638899046073; Tue, 07 Dec 2021 09:44:06 -0800 (PST) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:201:a783:e7e8:acf6:96a5]) by smtp.gmail.com with ESMTPSA id z14sm334890pfh.60.2021.12.07.09.44.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Dec 2021 09:44:05 -0800 (PST) From: Douglas Anderson To: Felipe Balbi , Greg Kroah-Hartman Cc: Matthias Kaehlcke , swboyd@chromium.org, Sandeep Maheswaram , Wesley Cheng , robdclark@chromium.org, Bjorn Andersson , linux-arm-msm@vger.kernel.org, Douglas Anderson , Andy Gross , Wesley Cheng , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: [PATCH] Revert "usb: dwc3: dwc3-qcom: Enable tx-fifo-resize property by default" Date: Tue, 7 Dec 2021 09:43:41 -0800 Message-Id: <20211207094327.1.Ie3cde3443039342e2963262a4c3ac36dc2c08b30@changeid> X-Mailer: git-send-email 2.34.1.400.ga245620fadb-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org This reverts commit cefdd52fa0455c0555c30927386ee466a108b060. On sc7180-trogdor class devices with 'fw_devlink=permissive' and KASAN enabled, you'll see a Use-After-Free reported at bootup. The root of the problem is that dwc3_qcom_of_register_core() is adding a devm-allocated "tx-fifo-resize" property to its device tree node using of_add_property(). The issue is that of_add_property() makes a _permanent_ addition to the device tree that lasts until reboot. That means allocating memory for the property using "devm" managed memory is a terrible idea since that memory will be freed upon probe deferral or device unbinding. Let's revert the patch since the system is still functional without it. The fact that of_add_property() makes a permanent change is extra fodder for those folks who were aruging that the device tree isn't really the right way to pass information between parts of the driver. It is an exercise left to the reader to submit a patch re-adding the new feature in a way that makes everyone happier. Fixes: cefdd52fa045 ("usb: dwc3: dwc3-qcom: Enable tx-fifo-resize property by default") Signed-off-by: Douglas Anderson --- This is an alternative to the patch ("usb: dwc3: dwc3-qcom: Avoid use-after-free when USB defers or unbinds") [1]. During the review of my patch fixing the use-after-free it was proposed that it would be better to revert the broken patch and it would be up to folks who cared about it to re-submit it without the problems. [1] https://lore.kernel.org/r/20211206152844.1.I411110cc99c1dd66b01aa9aa25651acf8ff55da1@changeid drivers/usb/dwc3/dwc3-qcom.c | 15 --------------- 1 file changed, 15 deletions(-) diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c index 9abbd01028c5..3cb01cdd02c2 100644 --- a/drivers/usb/dwc3/dwc3-qcom.c +++ b/drivers/usb/dwc3/dwc3-qcom.c @@ -649,7 +649,6 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev) struct dwc3_qcom *qcom = platform_get_drvdata(pdev); struct device_node *np = pdev->dev.of_node, *dwc3_np; struct device *dev = &pdev->dev; - struct property *prop; int ret; dwc3_np = of_get_compatible_child(np, "snps,dwc3"); @@ -658,20 +657,6 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev) return -ENODEV; } - prop = devm_kzalloc(dev, sizeof(*prop), GFP_KERNEL); - if (!prop) { - ret = -ENOMEM; - dev_err(dev, "unable to allocate memory for property\n"); - goto node_put; - } - - prop->name = "tx-fifo-resize"; - ret = of_add_property(dwc3_np, prop); - if (ret) { - dev_err(dev, "unable to add property\n"); - goto node_put; - } - ret = of_platform_populate(np, NULL, NULL, dev); if (ret) { dev_err(dev, "failed to register dwc3 core - %d\n", ret);