Use After Free Affecting kernel-modules-core package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.05% (18th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about Use After Free vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-RHEL9-KERNELMODULESCORE-7474219
  • published17 Jul 2024
  • disclosed12 Jul 2024

Introduced: 12 Jul 2024

CVE-2024-40900  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:9 kernel-modules-core.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-modules-core package and not the kernel-modules-core package as distributed by RHEL. See How to fix? for RHEL:9 relevant fixed versions and status.

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.

CVSS Scores

version 3.1