CVE-2024-49854
HighIn the Linux kernel, the following vulnerability has been resolved: block, bfq: fix uaf for accessing waker_bfqq after splitting After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe. Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder.
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-2024-49854 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
Affected versions
Linux kernel versions
4.19.323,
5.4.285,
5.10.227
and later are affected. No fixed version recorded yet.
References
The following references provide additional information about CVE-2024-49854 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/0780451f03bf518bc032a7c584de8f92e2d39d7f
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PatchKernel patch commithttps://git.kernel.org/stable/c/0b8bda0ff17156cd3f60944527c9d8c9f99f1583
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PatchKernel patch commithttps://git.kernel.org/stable/c/1ba0403ac6447f2d63914fb760c44a3b19c44eaf
Frequently asked questions
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What is CVE-2024-49854?
CVE-2024-49854 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) . It affects Linux kernel versions from 4.19.323 onward . CVE-2024-49854 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-2024-49854?
CVE-2024-49854 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-2024-49854?
No patch is currently available for CVE-2024-49854. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
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Is CVE-2024-49854 actively exploited?
No — CVE-2024-49854 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 →