CVE-2024-40900: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

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 products

• Linux Linux Kernel: from 5.19, before 6.1.95 (fixed in 6.1.95); from 6.2, before 6.6.35 (fixed in 6.6.35); from 6.7, before 6.9.6 (fixed in 6.9.6); version 6.10 only

Published 2024-07-12. Last modified 2026-08-04.