# CVE-2022-50657: riscv: mm: add missing memcpy in kasan_init

> Missing memory copy in RISC-V KASAN initialization causes page faults and system crashes when accessing shadow regions.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-50657, GHSA-jcqw-583m-jhjv, UBUNTU-CVE-2022-50657

## What is CVE-2022-50657?

CVE-2022-50657 is a vulnerability in Linux, published on 9 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

riscv: mm: add missing memcpy in kasan_init

Hi Atish,

It seems that the panic is due to the missing memcpy during kasan_init.
Could you please check whether this patch is helpful?

When doing kasan_populate, the new allocated base_pud/base_p4d should
contain kasan_early_shadow_{pud, p4d}'s content. Add the missing memcpy
to avoid page fault when read/write kasan shadow region.

Tested on:
 - qemu with sv57 and CONFIG_KASAN on.
 - qemu with sv48 and CONFIG_KASAN on.

## Which versions are affected by CVE-2022-50657?


## How do I fix CVE-2022-50657?

Apply the vendor's patch.

## Is CVE-2022-50657 being exploited?

There is no known exploitation of CVE-2022-50657 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-50657 and fix it if it is affected.

What it is: CVE-2022-50657 is a vulnerability in Linux, published on 9 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-50657 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-2022-50657/ (Markdown: https://insights.sbomify.com/CVE-2022-50657/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50657
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50657
- OSV: https://osv.dev/vulnerability/CVE-2022-50657

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50657/
Summaries are generated and may contain mistakes; the official description above is the record.