CVE-2026-89639
Description
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.
How to fix
- Linux Linux8b9b10fe5b8b492b27b9f4546742ea541a650213, 81fc3868a7f726980ff845c1d0d271051e5f0f45, 364b183230586a62660a7280c1eb20138338eeb5, 6.18.50, 6.13, 7.2 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Linux Linux | efbcecdecefc26fa062c0e8210533ccad7d6bd4a ≤ v < 8b9b10fe5b8b492b27b9f4546742ea541a650213, fa724e235cfdb0fb0bb427d0f9dfe864ae27403e ≤ v < 81fc3868a7f726980ff845c1d0d271051e5f0f45, fa724e235cfdb0fb0bb427d0f9dfe864ae27403e ≤ v < 364b183230586a62660a7280c1eb20138338eeb5, 6838bcac954487cc0a3c8a4ee1b3a3a30e244dc9, 75640976cf474eb41682a13f2dbe9534ac26ca50, 3513f3931c579ba2a715784c6dedc59e0d9282ee, 6.18.44 ≤ v < 6.18.50, 6.12.105 ≤ v < 6.13, 7.1.8 ≤ v < 7.2, 7.2 | 8b9b10fe5b8b492b27b9f4546742ea541a650213, 81fc3868a7f726980ff845c1d0d271051e5f0f45, 364b183230586a62660a7280c1eb20138338eeb5, 6.18.50, 6.13, 7.2 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.