CVE-2024-40900
HighIn 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 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-416CVE-2024-40900 is a Use After Free vulnerability
What is Use After Free?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE
References
The following references provide additional information about CVE-2024-40900 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/0fc75c5940fa634d84e64c93bfc388e1274ed013
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PatchKernel patch commithttps://git.kernel.org/stable/c/37e19cf86a520d65de1de9cb330415c332a40d19
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PatchKernel patch commithttps://git.kernel.org/stable/c/50d0e55356ba5b84ffb51c42704126124257e598
Frequently asked questions
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What is CVE-2024-40900?
CVE-2024-40900 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . CVE-2024-40900 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2024-40900?
CVE-2024-40900 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2024-40900?
No patch is currently available for CVE-2024-40900. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
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Is CVE-2024-40900 actively exploited?
No — CVE-2024-40900 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Use After Free (CWE-416)?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →