# CVE-2022-50774: crypto: qat - fix DMA transfer direction

> A bug in the Intel QAT crypto driver causes DMA mapping warnings and potential instability when CONFIG_DMA_API_DEBUG is enabled during self-tests.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Not stated
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-50774, GHSA-c9vq-m3c3-2m7g, UBUNTU-CVE-2022-50774

## What is CVE-2022-50774?

CVE-2022-50774 is a vulnerability in Linux, published on 24 Dec 2025. 

### Official 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 buffers are mapped with DMA_FROM_DEVICE.
Overlapping a read mapping with a write mapping is a valid case in
dma-coherent devices like QAT.
The function that frees and unmaps the buffers, qat_alg_free_bufl()
has been changed accordingly to the changes to the mapping function.

   DMA-API: 4xxx 0000:06:00.0: cacheline tracking EEXIST, overlapping mappings aren't supported
   WARNING: CPU: 53 PID: 4362 at kernel/dma/debug.c:570 add_dma_entry+0x1e9/0x270
   ...
   Call Trace:
   dma_map_page_attrs+0x82/0x2d0
   ? preempt_count_add+0x6a/0xa0
   qat_alg_sgl_to_bufl+0x45b/0x990 [intel_qat]
   qat_alg_aead_dec+0x71/0x250 [intel_qat]
   crypto_aead_decrypt+0x3d/0x70
   test_aead_vec_cfg+0x649/0x810
   ? number+0x310/0x3a0
   ? vsnprintf+0x2a3/0x550
   ? scnprintf+0x42/0x70
   ? valid_sg_divisions.constprop.0+0x86/0xa0
   ? test_aead_vec+0xdf/0x120
   test_aead_vec+0xdf/0x120
   alg_test_aead+0x185/0x400
   alg_test+0x3d8/0x500
   ? crypto_acomp_scomp_free_ctx+0x30/0x30
   ? __schedule+0x32a/0x12a0
   ? ttwu_queue_wakelist+0xbf/0x110
   ? _raw_spin_unlock_irqrestore+0x23/0x40
   ? try_to_wake_up+0x83/0x570
   ? _raw_spin_unlock_irqrestore+0x23/0x40
   ? __set_cpus_allowed_ptr_locked+0xea/0x1b0
   ? crypto_acomp_scomp_free_ctx+0x30/0x30
   cryptomgr_test+0x27/0x50
   kthread+0xe6/0x110
   ? kthread_complete_and_exit+0x20/0x20
   ret_from_fork+0x1f/0x30

## Which versions are affected by CVE-2022-50774?


## How do I fix CVE-2022-50774?

Apply the vendor's patch.

## Is CVE-2022-50774 being exploited?

There is no known exploitation of CVE-2022-50774 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-50774 and fix it if it is affected.

What it is: CVE-2022-50774 is a vulnerability in Linux, published on 24 Dec 2025. 
Exploitation: There is no known exploitation of CVE-2022-50774 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-50774/ (Markdown: https://insights.sbomify.com/CVE-2022-50774/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50774
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50774
- OSV: https://osv.dev/vulnerability/CVE-2022-50774

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50774/
Summaries are generated and may contain mistakes; the official description above is the record.