Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Jia-Ju Bai <baijiaju@tsinghua.edu.cn>
Subject: [BUG] crypto: qat: accessing the data mapped to streaming DMA
To:     giovanni.cabiddu@intel.com, herbert@gondor.apana.org.au,
        davem@davemloft.net, ardb@kernel.org, horia.geanta@nxp.com,
        geert+renesas@glider.be, ebiggers@google.com
Cc:     qat-linux@intel.com, linux-crypto@vger.kernel.org,
        linux-kernel@vger.kernel.org
Message-ID: <7bda4db1-cca2-f6f1-4b70-52d2d25f8d2d@tsinghua.edu.cn>
Date:   Sun, 2 Aug 2020 22:35:59 +0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101
 Thunderbird/68.4.1
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Content-Language: en-US
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In qat_alg_sgl_to_bufl(), "bufl" and "buflout" are mapped to streaming DMA:
   blp = dma_map_single(dev, bufl, sz, DMA_TO_DEVICE);
   bloutp = dma_map_single(dev, buflout, sz_out, DMA_TO_DEVICE);

Then "bufl" and "buflout" are accessed at some places, such as:
   bufl->bufers[y].len = sg->length;
   bufl->num_bufs = sg_nctr;
   bufers = buflout->bufers;
   buflout->num_bufs = sg_nctr;

These accesses may cause data inconsistency between CPU cache and hardware.

I am not sure how to properly fix this problem, and thus I only report it.


Best wishes,
Jia-Ju Bai