# CVE-2025-68293: mm/huge\_memory: fix NULL pointer deference when splitting folio

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-12-16 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.9

## Description

In the Linux kernel, the following vulnerability has been resolved: mm/huge_memory: fix NULL pointer deference when splitting folio Commit c010d47f107f ("mm: thp: split huge page to any lower order pages") introduced an early check on the folio's order via mapping->flags before proceeding with the split work. This check introduced a bug: for shmem folios in the swap cache and truncated folios, the mapping pointer can be NULL. Accessing mapping->flags in this state leads directly to a NULL pointer dereference. This commit fixes the issue by moving the check for mapping != NULL before any attempt to access mapping->flags.

## 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.
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  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-68293

## 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/592db83615a9f0164472ec789c2ed34ad35f732f
- https://git.kernel.org/stable/c/d1b83fbacd4397a1d2f8c6b13427a8636ae2b307
- https://git.kernel.org/stable/c/cff47b9e39a6abf03dde5f4f156f841b0c54bba0

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Page: https://cve.now/CVE-2025-68293
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