CVE-2024-31076
Intel x86 Linux Kernel CPU Vector Leak
Description
In the Linux kernel, the following vulnerability has been resolved: genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline The absence of IRQD_MOVE_PCNTXT prevents immediate effectiveness of interrupt affinity reconfiguration via procfs. Instead, the change is deferred until the next instance of the interrupt being triggered on the original CPU. When the interrupt next triggers on the original CPU, the new affinity is enforced within __irq_move_irq(). A vector is allocated from the new CPU, but the old vector on the original CPU remains and is not immediately reclaimed. Instead, apicd->move_in_progress is flagged, and the reclaiming process is delayed until the next trigger of the interrupt on the new CPU. Upon the subsequent triggering of the interrupt on the new CPU, irq_complete_move() adds a task to the old CPU's vector_cleanup list if it remains online. Subsequently, the timer on the old CPU iterates over its vector_cleanup list, reclaiming old vectors. However, a rare scenario arises if the old CPU is outgoing before the interrupt triggers again on the new CPU. In that case irq_force_complete_move() is not invoked on the outgoing CPU to reclaim the old apicd->prev_vector because the interrupt isn't currently affine to the outgoing CPU, and irq_needs_fixup() returns false. Even though __vector_schedule_cleanup() is later called on the new CPU, it doesn't reclaim apicd->prev_vector; instead, it simply resets both apicd->move_in_progress and apicd->prev_vector to 0. As a result, the vector remains unreclaimed in vector_matrix, leading to a CPU vector leak. To address this issue, move the invocation of irq_force_complete_move() before the irq_needs_fixup() call to reclaim apicd->prev_vector, if the interrupt is currently or used to be affine to the outgoing CPU. Additionally, reclaim the vector in __vector_schedule_cleanup() as well, following a warning message, although theoretically it should never see apicd->move_in_progress with apicd->prev_cpu pointing to an offline CPU.
INFO
Published Date :
June 21, 2024, 11:15 a.m.
Last Modified :
July 15, 2024, 7:15 a.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
Exploitability Score :
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-2024-31076
.
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).
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The following list is the news that have been mention
CVE-2024-31076
vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2024-31076
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.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 15, 2024
Action Type Old Value New Value Removed Reference kernel.org https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 27, 2024
Action Type Old Value New Value Added Reference kernel.org https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html [No types assigned] -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 21, 2024
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline The absence of IRQD_MOVE_PCNTXT prevents immediate effectiveness of interrupt affinity reconfiguration via procfs. Instead, the change is deferred until the next instance of the interrupt being triggered on the original CPU. When the interrupt next triggers on the original CPU, the new affinity is enforced within __irq_move_irq(). A vector is allocated from the new CPU, but the old vector on the original CPU remains and is not immediately reclaimed. Instead, apicd->move_in_progress is flagged, and the reclaiming process is delayed until the next trigger of the interrupt on the new CPU. Upon the subsequent triggering of the interrupt on the new CPU, irq_complete_move() adds a task to the old CPU's vector_cleanup list if it remains online. Subsequently, the timer on the old CPU iterates over its vector_cleanup list, reclaiming old vectors. However, a rare scenario arises if the old CPU is outgoing before the interrupt triggers again on the new CPU. In that case irq_force_complete_move() is not invoked on the outgoing CPU to reclaim the old apicd->prev_vector because the interrupt isn't currently affine to the outgoing CPU, and irq_needs_fixup() returns false. Even though __vector_schedule_cleanup() is later called on the new CPU, it doesn't reclaim apicd->prev_vector; instead, it simply resets both apicd->move_in_progress and apicd->prev_vector to 0. As a result, the vector remains unreclaimed in vector_matrix, leading to a CPU vector leak. To address this issue, move the invocation of irq_force_complete_move() before the irq_needs_fixup() call to reclaim apicd->prev_vector, if the interrupt is currently or used to be affine to the outgoing CPU. Additionally, reclaim the vector in __vector_schedule_cleanup() as well, following a warning message, although theoretically it should never see apicd->move_in_progress with apicd->prev_cpu pointing to an offline CPU. Added Reference kernel.org https://git.kernel.org/stable/c/a40209d355afe4ed6d533507838c9e5cd70a76d8 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/f5f4675960609d8c5ee95f027fbf6ce380f98372 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/6752dfcfff3ac3e16625ebd3f0ad9630900e7e76 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/9eeda3e0071a329af1eba15f4e57dc39576bb420 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/e9c96d01d520498b169ce734a8ad1142bef86a30 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/59f86a2908380d09cdc726461c0fbb8d8579c99f [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/ebfb16fc057a016abb46a9720a54abf0d4f6abe1 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/a6c11c0a5235fb144a65e0cb2ffd360ddc1f6c32 [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-2024-31076
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-2024-31076
weaknesses.