CVE-2024-42245
MediumIn the Linux kernel, the following vulnerability has been resolved: Revert "sched/fair: Make sure to try to detach at least one movable task" This reverts commit b0defa7ae03ecf91b8bfd10ede430cff12fcbd06. b0defa7ae03ec changed the load balancing logic to ignore env.max_loop if all tasks examined to that point were pinned. The goal of the patch was to make it more likely to be able to detach a task buried in a long list of pinned tasks. However, this has the unfortunate side effect of creating an O(n) iteration in detach_tasks(), as we now must fully iterate every task on a cpu if all or most are pinned. Since this load balance code is done with rq lock held, and often in softirq context, it is very easy to trigger hard lockups. We observed such hard lockups with a user who affined O(10k) threads to a single cpu. When I discussed this with Vincent he initially suggested that we keep the limit on the number of tasks to detach, but increase the number of tasks we can search. However, after some back and forth on the mailing list, he recommended we instead revert the original patch, as it seems likely no one was actually getting hit by the original issue.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-667CVE-2024-42245 is a Improper Locking vulnerability
What is Improper Locking?
The product does not properly acquire or release a lock, which can lead to unexpected behaviour. Learn more on MITRE CWE
References
The following references provide additional information about CVE-2024-42245 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/0fa6dcbfa2e2b97c1e6febbea561badf0931a38b
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PatchKernel patch commithttps://git.kernel.org/stable/c/1e116c18e32b035a2d1bd460800072c8bf96bc44
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PatchKernel patch commithttps://git.kernel.org/stable/c/2feab2492deb2f14f9675dd6388e9e2bf669c27a
Frequently asked questions
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What is CVE-2024-42245?
CVE-2024-42245 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Improper Locking flaw (CWE-667) . CVE-2024-42245 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-2024-42245?
CVE-2024-42245 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2024-42245?
No patch is currently available for CVE-2024-42245. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
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Is CVE-2024-42245 actively exploited?
No — CVE-2024-42245 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 Improper Locking (CWE-667)?
The product does not properly acquire or release a lock, which can lead to unexpected behaviour. View CWE-667 on MITRE CWE →