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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 07044C7115C for ; Wed, 25 Jun 2025 04:45:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:Mime-Version:References:In-Reply-To:Message-Id:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=oxhKtwaA63Fos0S2DVop/2E5u/CuV9J2sGATS1cbp6I=; b=DcuCVryLUX8cwrIbNH6utAxmS7 8KuveCDUJ2JBxvWUQiaLd6me37ZwbNAfETkJDYH1pW3CD9v98ZZEanOVke1/yvdXBQSWDZG6Gr8lM Vm3PLu/n6PFs+CZ5Fg3L7jai1LLHeAkH0QozaPDPyqFj8JDD03qumTHQnUH0opdVRoK0LyopUQs62 SjVYrblygoRr/SG6OdWKRbhP5FClGfqie3rNk/ffrkO48ZtrJPaVPYf3fVbPNG7gmeZwMOltP4mqr l9DlxeYcozZp52puuXoyIrAyaCdK99kbX58C1i1TMhWnD2HKAkr8rkfyfYvFTZ6uZlOLR5OhzMSvn eRNp2nSA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uUI0g-00000007XUN-17jg; Wed, 25 Jun 2025 04:45:22 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uUHyN-00000007X8z-2sTW; Wed, 25 Jun 2025 04:42:59 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id E0047614C6; Wed, 25 Jun 2025 04:42:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28CA3C4CEEA; Wed, 25 Jun 2025 04:42:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750826577; bh=s0Uf4rDKwjy1dsp7E1aDOpTFmlXsypuC2uqpLNZ5DKY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=kpr1HQMca3yxYzZRwgASl7KM9m5QByPLHuYDp8quWxFse6APaNTIh2d/R6GX4wQYF zlMCV4rLSly8vPfih+25aD7oiEhIKwj+FtCtQHmXTIFp/SDYmrq3xdM37PQISvprY4 W07TOosv3dtwmSUeVemySj27HYVuIaTmksNRRLbD+Y44sPaK7s+/fycu6HqutouwWu +07mC9cMZ/h8A0LObzrYf4Z4Ajq874qs71LWj6KJVM0EM+aoy95qk7G5Q5tQoUD3We D2uO5L/oFgb6+hQYARDgkC7Xy8ugK+EpTVHaDrCI3hgXWr0GBaCRKCdXShDgD37cWK R32u0jXlYYLNQ== Date: Wed, 25 Jun 2025 13:42:54 +0900 From: Masami Hiramatsu (Google) To: Sergey Senozhatsky Cc: Ulf Hansson , Chaotian Jing , Matthias Brugger , AngeloGioacchino Del Regno , Tomasz Figa , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: Re: [PATCH] mtk-sd: Prevent memory corruption from DMA map failure Message-Id: <20250625134254.7cbd72feb80d8d050f2f005d@kernel.org> In-Reply-To: References: <174972756982.3337526.6755001617701603082.stgit@mhiramat.tok.corp.google.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Wed, 25 Jun 2025 13:13:18 +0900 Sergey Senozhatsky wrote: > On (25/06/25 12:56), Sergey Senozhatsky wrote: > > On (25/06/12 20:26), Masami Hiramatsu (Google) wrote: > > [..] > > > @@ -1466,8 +1471,18 @@ static void msdc_ops_request(struct mmc_host *mmc, struct mmc_request *mrq) > > > WARN_ON(!host->hsq_en && host->mrq); > > > host->mrq = mrq; > > > > > > - if (mrq->data) > > > + if (mrq->data) { > > > msdc_prepare_data(host, mrq->data); > > > + if (!msdc_data_prepared(mrq->data)) { > > > + /* > > > + * Failed to prepare DMA area, fail fast before > > > + * starting any commands. > > > + */ > > > + mrq->cmd->error = -ENOSPC; > > > + mmc_request_done(mmc_from_priv(host), mrq); > > > > Do we end up having a stale/dangling host->mrq pointer here? > > Something like this maybe? Good catch! I thought it is cleared in mmc_request_done(), but not. I agree we need to clean it up since it is set in msdc_ops_request(). Reviewed-by: Masami Hiramatsu (Google) Thanks, > > --- > > diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c > index b12cfb9a5e5f..46bb770ace41 100644 > --- a/drivers/mmc/host/mtk-sd.c > +++ b/drivers/mmc/host/mtk-sd.c > @@ -1498,6 +1498,7 @@ static void msdc_ops_request(struct mmc_host *mmc, struct mmc_request *mrq) > */ > mrq->cmd->error = -ENOSPC; > mmc_request_done(mmc_from_priv(host), mrq); > + host->mrq = NULL; > return; > } > } -- Masami Hiramatsu (Google)