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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD0FFC433F5 for ; Thu, 25 Nov 2021 12:48:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352866AbhKYMvj (ORCPT ); Thu, 25 Nov 2021 07:51:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352392AbhKYMti (ORCPT ); Thu, 25 Nov 2021 07:49:38 -0500 Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 883BEC06173E for ; Thu, 25 Nov 2021 04:46:27 -0800 (PST) Received: by mail-wr1-x435.google.com with SMTP id a9so11373936wrr.8 for ; Thu, 25 Nov 2021 04:46:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=+gncLq6zW+uaJXb12G46JXw6L/TdgNucdLmqfgrp0+o=; b=rVodE+/WNoi3Sfxs2jcd7569XzqUkSwJRQSvzGdzNymel1x2JaHWRq1fgKr7eF3A9Q RQfG/xGxSAKWtN4jiaZIsLePPV7uZo0m5qWSrRyDEbgATRYH0/dMZ1Aj7qqRpXfdPnFx 1dWEDX8Jbq9RMkIXAb32vTtdUCkIQxS28TCzIMzmz1jxuXWxbCBE13Hz1YNUHsfAPa88 6izLyPZ6u6oy4uaDAtR7DCfAQcJpX24x7aFIc8oRtd2c5h2Rb6QNMR4QBaK9DMJoCeag pPdaKnPHZ6oItc6bls2fxY/RbX1bGO239f3i7+X2ddbeEEUtJEbBE95ZIH0U0GICy2l2 Yipg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=+gncLq6zW+uaJXb12G46JXw6L/TdgNucdLmqfgrp0+o=; b=sIkaIPm7MdXfzElWG1dJMWOMC9kR0PeGWiP6l5uO9t4bSZmOlPiKZBv9uDuRft1PgE 3nhSpMQKp/8uucNXMEMwHvY9mfPM3wUF5J7eT2l0iNTFKEi30tjEcGgdoG1wyBLhf4Rr cDlCPT54B9BsE7xhOMV+PPiF0Xe2jRfkjkmUJMESuii2O1GU5OimW60fPQk28oXQ1WvK tUYgSBDtEWLHXE/+V5ReAvNONLWPGcTK0xprqt4rLJWv9jY6D/LeUAN8y0QwtuFzCU7O ujZz/1Kp33ml/1zqZZQILPyV8p1UEQcGvgfCFxoQxbg8GNo4yJOKklfl2Qc7HGSIs8W3 puRw== X-Gm-Message-State: AOAM532eoMm/QO9jgiV0wRO5cgE1VAp3AEAUZ0cC9N3Do1hArMDXPuu/ MpDTHV6lAN4AmEeZP1Vj+0C4oQ== X-Google-Smtp-Source: ABdhPJywL2FUFo74HYcfnZb781d5v7oT4P61QKWt5azK2yVdzqQXHeY2CdmiviPFB2uADOpu1K57ow== X-Received: by 2002:adf:8b1e:: with SMTP id n30mr6166068wra.75.1637844386075; Thu, 25 Nov 2021 04:46:26 -0800 (PST) Received: from google.com ([2.31.167.18]) by smtp.gmail.com with ESMTPSA id x21sm7408221wmc.14.2021.11.25.04.46.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Nov 2021 04:46:25 -0800 (PST) Date: Thu, 25 Nov 2021 12:46:23 +0000 From: Lee Jones To: Greg KH Cc: devel@driverdev.osuosl.org, arve@android.com, stable@vger.kernel.org, riandrews@android.com, labbott@redhat.com, sumit.semwal@linaro.org Subject: Re: [PATCH 1/1] staging: ion: Prevent incorrect reference counting behavour Message-ID: References: <20211125120234.67987-1-lee.jones@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Thu, 25 Nov 2021, Greg KH wrote: > On Thu, Nov 25, 2021 at 12:02:34PM +0000, Lee Jones wrote: > > Supply additional checks in order to prevent unexpected results. > > > > Fixes: b892bf75b2034 ("ion: Switch ion to use dma-buf") > > Signed-off-by: Lee Jones > > --- > > drivers/staging/android/ion/ion.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c > > index 806e9b30b9dc8..30f359faba575 100644 > > --- a/drivers/staging/android/ion/ion.c > > +++ b/drivers/staging/android/ion/ion.c > > @@ -509,6 +509,9 @@ static void *ion_handle_kmap_get(struct ion_handle *handle) > > void *vaddr; > > > > if (handle->kmap_cnt) { > > + if (handle->kmap_cnt + 1 < handle->kmap_cnt) > > What about using the nice helpers in overflow.h for this? I haven't heard of these before. Looks like they're not widely used. I'll try them out and see how they go. > > + return ERR_PTR(-EOVERFLOW); > > + > > handle->kmap_cnt++; > > return buffer->vaddr; > > } > > What stable kernel branch(es) is this for? I assumed your magic scripts could determine this from the Fixes: tag. I'll be more explicit in v2. -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog