# CVE-2022-49699: filemap: Handle sibling entries in filemap_get_read_batch()

Status: published. Published: 2025-02-26. Updated: 2026-11-05.

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

filemap: Handle sibling entries in filemap_get_read_batch()

If a read races with an invalidation followed by another read, it is
possible for a folio to be replaced with a higher-order folio.  If that
happens, we'll see a sibling entry for the new folio in the next iteration
of the loop.  This manifests as a NULL pointer dereference while holding
the RCU read lock.

Handle this by simply returning.  The next call will find the new folio
and handle it correctly.  The other ways of handling this rare race are
more complex and it's just not worth it.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ cbd59c48ae2bcadc4a7599c29cf32fd3f9b78251; < a66f131d30e53000f08301776bf85c912ef47aad (affected, git); ≥ cbd59c48ae2bcadc4a7599c29cf32fd3f9b78251; < cb995f4eeba9d268fd4b56c2423ad6c1d1ea1b82 (affected, git). Source: CNA: Linux
- Linux / Linux: 5.12 (affected); ≥ 0; < 5.12 (unaffected, semver); ≥ 5.18.8; ≤ 5.18.* (unaffected, semver); ≥ 5.19; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: 0.23% as of 2026-11-05; percentile 13.72%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: Not reported

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/a66f131d30e53000f08301776bf85c912ef47aad (CNA: Linux)

- https://git.kernel.org/stable/c/cb995f4eeba9d268fd4b56c2423ad6c1d1ea1b82 (CNA: Linux)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2022-49699; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2022-49699; retrieved 2026-11-05; source updated Not reported

Revision: 108aed802d2f0fa0ddf7112a0c7fa7a9b9b73f7f3d42a37e2d8ec6794982d366

Canonical: https://y2.dev/cve/CVE-2022-49699

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