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=-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 B7730C388F9 for ; Tue, 3 Nov 2020 21:50:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 608A521556 for ; Tue, 3 Nov 2020 21:50:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604440205; bh=Hd4XbZiTS7NDDUJEkgjX4l37jNWVlR3STL53BlmaYcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nkQmDbipl9JhGUc2vu44tdEmT+CspwKM3Z1REUXkCrB5q25ZrTNF90NZrB2VF9FNw 8b2C6c9mVqy6zoFbO6//vDa0lFtzzUCo/Hgj7fdEpS/au9PBcYr2kvVACFYpfyHiLY JOLxmUOcB9bhyd6j4eErOmKAO2xKTGBqMB9ThSG0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732008AbgKCVuE (ORCPT ); Tue, 3 Nov 2020 16:50:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:42144 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730816AbgKCUtV (ORCPT ); Tue, 3 Nov 2020 15:49:21 -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 08D5C22404; Tue, 3 Nov 2020 20:49:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604436560; bh=Hd4XbZiTS7NDDUJEkgjX4l37jNWVlR3STL53BlmaYcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BILkHH/n7aqrbyRDcVISO7MBSJbfjPO5GC9TVnDaaDEVNwCZDfr/xbzD+FTjIPOih bdJgEZ4YKt8AnpTgREzuXbWNziXR+JM3uJZ5OiWCEodd77h1ZyEmD58rRxBkUMQ40C fzDfe4RhgzSl76nVgMluQQh8PhkFYuzFtIwk5XCQ= 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 5.9 265/391] dmaengine: dma-jz4780: Fix race in jz4780_dma_tx_status Date: Tue, 3 Nov 2020 21:35:16 +0100 Message-Id: <20201103203404.904108363@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203348.153465465@linuxfoundation.org> References: <20201103203348.153465465@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -639,11 +639,11 @@ static enum dma_status jz4780_dma_tx_sta unsigned long flags; unsigned long residue = 0; + 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) { @@ -660,6 +660,7 @@ 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; }