CVE-2026-89639

In the Linux kernel, the following vulnerability has been resolved: cifs: use cifs_invalidate_cache() in cifs_do_truncate() for O_TRUNC cifs_do_truncate() is invoked from cifs_open() without i_rwsem, so it cannot use cifs_resize_file_locked() to perform a proper fscache cookie resize. Instead, add cifs_invalidate_cache() after cifs_setsize(). cifs_invalidate_cache() calls fscache_invalidate(), which works without holding i_rwsem: it unconditionally increments inval_counter and sets FSCACHE_COOKIE_NO_DATA_TO_READ, ensuring that stale cached data is not served once the cookie is later activated by fscache_use_cookie(). Truncation to zero leaves no valid cached data, making invalidation the correct semantic here.

CVSS v3 7.1 HIGH

7.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.2

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/364b183230586a62660a7280c1eb20138338eeb5
https://git.kernel.org/stable/c/81fc3868a7f726980ff845c1d0d271051e5f0f45
https://git.kernel.org/stable/c/8b9b10fe5b8b492b27b9f4546742ea541a650213

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-11 20:19

Updated : 2026-09-13 07:17

NVD link : CVE-2026-89639

Mitre link : CVE-2026-89639

CVE.ORG link : CVE-2026-89639

JSON object : View

Products Affected

No product.

CWE

No CWE.

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