CVE-2025-71309

/// Technical 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@p

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References