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 035C9C388F7 for ; Tue, 3 Nov 2020 21:06:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C0BD722226 for ; Tue, 3 Nov 2020 21:06:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604437615; bh=DvEpMmqZWochAGWFLIfDIUJdSv6B7FqOuLt4kj04R5A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FEDfuMSwxnP4aUZRtxOjVb7VpLYyyOtZ2MrLJ8yIjK/jT0uUbt8JeUM5ekWE4NWRU BU9R4Hof6WCGwQlyRxpUUAbCpv1bCnpNy1ae9GE+97mrrZvrP8qi1Oreg1CK747lDK 6HEOlXDh6Ik23Qh8gNIBNE8xOmPHp4zZhfeLspTo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388230AbgKCVGy (ORCPT ); Tue, 3 Nov 2020 16:06:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:45798 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388212AbgKCVGq (ORCPT ); Tue, 3 Nov 2020 16:06:46 -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 5BBDD206B5; Tue, 3 Nov 2020 21:06:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604437605; bh=DvEpMmqZWochAGWFLIfDIUJdSv6B7FqOuLt4kj04R5A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mdffgN+yWTq4+swyXJXT8rUz77JcXPZOQnNZxQKav3pRZo4VbPJ4F91IlTYuaIirS 4RJ0Gdr/ZY2JDOV6fq896XEbYtu0xfrwZb0PMQynMQwVyut0cAl/Yk0WElQfeUaasf /UsSHF+luwKQEj+iiAPgTinvWoByi2q36RI0vDMo= 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 4.19 148/191] dmaengine: dma-jz4780: Fix race in jz4780_dma_tx_status Date: Tue, 3 Nov 2020 21:37:20 +0100 Message-Id: <20201103203246.582987354@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203232.656475008@linuxfoundation.org> References: <20201103203232.656475008@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 @@ -574,11 +574,11 @@ 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) { @@ -595,6 +595,7 @@ 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; }