CVE-2024-40900
Medium
Elevated severity or exploit probability.
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2024-07-12 — Published (NVD)
- 2026-08-04 — Last modified (NVD)
Description
In the Linux kernel, the following vulnerability has been resolved: cachefiles: remove requests from xarray during flushing requests Even with CACHEFILES_DEAD set, we can still read the requests, so in the following concurrency the request may be used after it has been freed: mount | daemon_thread1 | daemon_thread2 ------------------------------------------------------------ cachefiles_ondemand_init_object cachefiles_ondemand_send_req REQ_A = kzalloc(sizeof(*req) + data_len) wait_for_completion(&REQ_A->done) cachefiles_daemon_read cachefiles_ondemand_daemon_read // close dev fd cachefiles_flush_reqs complete(&REQ_A->done) kfree(REQ_A) xa_lock(&cache->reqs); cachefiles_ondemand_select_req req->msg.opcode != CACHEFILES_OP_READ // req use-after-free !!! xa_unlock(&cache->reqs); xa_destroy(&cache->reqs) Hence remove requests from cache->reqs when flushing them to avoid accessing freed requests.
Affected
References
- https://git.kernel.org/stable/c/0fc75c5940fa634d84e64c93bfc388e1274ed013
- https://git.kernel.org/stable/c/37e19cf86a520d65de1de9cb330415c332a40d19
- https://git.kernel.org/stable/c/50d0e55356ba5b84ffb51c42704126124257e598
- https://git.kernel.org/stable/c/9f13aacdd4ee9a7644b2a3c96d67113cd083c9c7
- https://git.kernel.org/stable/c/0fc75c5940fa634d84e64c93bfc388e1274ed013
- https://git.kernel.org/stable/c/37e19cf86a520d65de1de9cb330415c332a40d19
- https://git.kernel.org/stable/c/50d0e55356ba5b84ffb51c42704126124257e598
- https://git.kernel.org/stable/c/9f13aacdd4ee9a7644b2a3c96d67113cd083c9c7
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html