From patchwork Mon Nov 9 12:54:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 322800 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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 D9BAAC4741F for ; Mon, 9 Nov 2020 13:03:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D6FE2076E for ; Mon, 9 Nov 2020 13:03:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604927031; bh=KWaRCCHd41F6UqxgvZjcc7BERVdpeQtdTzZKmogmbxk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hggQq+mo9B6TELD+KfBj9uMExlx6e4BtVjUGgDJNWqDG9hZy4h+83FYi89lHC/XVf lTeY+QAAhc/LDAp2m1Krc9LB+5LirXCd0++quSKmHjgpodFyCjN5QAP+pDWwudwD9Y /5V1WOzyWL/8iLuDkt8q9Vjh5/N+zBLVBb9v+tsM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730082AbgKINDq (ORCPT ); Mon, 9 Nov 2020 08:03:46 -0500 Received: from mail.kernel.org ([198.145.29.99]:56432 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730565AbgKINCs (ORCPT ); Mon, 9 Nov 2020 08:02:48 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 B9E04221F1; Mon, 9 Nov 2020 13:02:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604926968; bh=KWaRCCHd41F6UqxgvZjcc7BERVdpeQtdTzZKmogmbxk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1YOkhjYvqgrIezFqqExhMj6JZzrE2Zo/vr0tSTfVaM8JpltTbTjK2Bu/z04onI4iW XISCgaXo3/fqHyFrowNpDzpd/zkm2TNl+cgAkg5GH2IrOsZv9x8G7u8Yp0+y5lfk2h Y/hvQrPi+c2bWbYX3DZOt5m4aXnLm96jBO0yVTxQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Cercueil , Artur Rojek , Vinod Koul Subject: [PATCH 4.9 065/117] dmaengine: dma-jz4780: Fix race in jz4780_dma_tx_status Date: Mon, 9 Nov 2020 13:54:51 +0100 Message-Id: <20201109125028.752789672@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201109125025.630721781@linuxfoundation.org> References: <20201109125025.630721781@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paul Cercueil commit baf6fd97b16ea8f981b8a8b04039596f32fc2972 upstream. The jz4780_dma_tx_status() function would check if a channel's cookie state was set to 'completed', and if not, it would enter the critical section. However, in that time frame, the jz4780_dma_chan_irq() function was able to set the cookie to 'completed', and clear the jzchan->vchan pointer, which was deferenced in the critical section of the first function. Fix this race by checking the channel's cookie state after entering the critical function and not before. Fixes: d894fc6046fe ("dmaengine: jz4780: add driver for the Ingenic JZ4780 DMA controller") Cc: stable@vger.kernel.org # v4.0 Signed-off-by: Paul Cercueil Reported-by: Artur Rojek Tested-by: Artur Rojek Link: https://lore.kernel.org/r/20201004140307.885556-1-paul@crapouillou.net Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/dma-jz4780.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/dma/dma-jz4780.c +++ b/drivers/dma/dma-jz4780.c @@ -567,11 +567,11 @@ static enum dma_status jz4780_dma_tx_sta enum dma_status status; unsigned long flags; + spin_lock_irqsave(&jzchan->vchan.lock, flags); + status = dma_cookie_status(chan, cookie, txstate); if ((status == DMA_COMPLETE) || (txstate == NULL)) - return status; - - spin_lock_irqsave(&jzchan->vchan.lock, flags); + goto out_unlock_irqrestore; vdesc = vchan_find_desc(&jzchan->vchan, cookie); if (vdesc) { @@ -588,6 +588,7 @@ static enum dma_status jz4780_dma_tx_sta && jzchan->desc->status & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT)) status = DMA_ERROR; +out_unlock_irqrestore: spin_unlock_irqrestore(&jzchan->vchan.lock, flags); return status; }