CVE-2024-42245
Linux Kernel Sched/Fair Load Balancing Denial of Service
Description
In 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.
INFO
Published Date :
Aug. 7, 2024, 4:15 p.m.
Last Modified :
Aug. 8, 2024, 2:53 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2024-42245.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2024-42245 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2024-42245 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Aug. 08, 2024
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://git.kernel.org/stable/c/0fa6dcbfa2e2b97c1e6febbea561badf0931a38b No Types Assigned https://git.kernel.org/stable/c/0fa6dcbfa2e2b97c1e6febbea561badf0931a38b Patch Changed Reference Type https://git.kernel.org/stable/c/1e116c18e32b035a2d1bd460800072c8bf96bc44 No Types Assigned https://git.kernel.org/stable/c/1e116c18e32b035a2d1bd460800072c8bf96bc44 Patch Changed Reference Type https://git.kernel.org/stable/c/2feab2492deb2f14f9675dd6388e9e2bf669c27a No Types Assigned https://git.kernel.org/stable/c/2feab2492deb2f14f9675dd6388e9e2bf669c27a Patch Changed Reference Type https://git.kernel.org/stable/c/d467194018dd536fe6c65a2fd3aedfcdb1424903 No Types Assigned https://git.kernel.org/stable/c/d467194018dd536fe6c65a2fd3aedfcdb1424903 Patch Added CWE NIST CWE-667 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.1 up to (excluding) 6.1.100 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.41 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.9.10 -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 07, 2024
Action Type Old Value New Value Added Description In 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. Added Reference kernel.org https://git.kernel.org/stable/c/d467194018dd536fe6c65a2fd3aedfcdb1424903 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/1e116c18e32b035a2d1bd460800072c8bf96bc44 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/0fa6dcbfa2e2b97c1e6febbea561badf0931a38b [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/2feab2492deb2f14f9675dd6388e9e2bf669c27a [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2024-42245 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2024-42245
weaknesses.