Use After Free Affecting kernel-rt package, versions *
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Test your applications- Snyk ID SNYK-CENTOS7-KERNELRT-7523606
- published 17 Jul 2024
- disclosed 12 Jul 2024
Introduced: 12 Jul 2024
CVE-2024-40900 Open this link in a new tabHow to fix?
There is no fixed version for Centos:7 kernel-rt.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-rt package and not the kernel-rt package as distributed by Centos.
See How to fix? for Centos:7 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.
References
- https://access.redhat.com/security/cve/CVE-2024-40900
- 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