CVE-2022-50774

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

crypto: qat - fix DMA transfer direction

When CONFIG_DMA_API_DEBUG is selected, while running the crypto self

test on the QAT crypto algorithms, the function add_dma_entry() reports

a warning similar to the one below, saying that overlapping mappings

are not supported. This occurs in tests where the input and the output

scatter list point to the same buffers (i.e. two different scatter lists

which point to the same chunks of memory).

The logic that implements the mapping uses the flag DMA_BIDIRECTIONAL

for both the input and the output scatter lists which leads to

overlapped write mappings. These are not supported by the DMA layer.

Fix by specifying the correct DMA transfer directions when mapping

buffers. For in-place operations where the input scatter list

matches the output scatter list, buffers are mapped once with

DMA_BIDIRECTIONAL, otherwise input buffers are mapped using the flag

DMA_TO_DEVICE and output buf

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References