2020-08-02 14:39:07

by Jia-Ju Bai

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Subject: [BUG] crypto: qat: accessing the data mapped to streaming DMA

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