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.
Metrics
Affected Vendors & Products
References
History
Sat, 16 Nov 2024 02:45:00 +0000
Type | Values Removed | Values Added |
---|---|---|
CPEs | cpe:/a:redhat:rhel_eus:9.4 |
Wed, 13 Nov 2024 15:00:00 +0000
Type | Values Removed | Values Added |
---|---|---|
First Time appeared |
Redhat rhel Eus
|
|
CPEs | cpe:/a:redhat:rhel_eus:9.2 cpe:/a:redhat:rhel_eus:9.2::nfv |
|
Vendors & Products |
Redhat rhel Eus
|
Wed, 13 Nov 2024 02:30:00 +0000
Type | Values Removed | Values Added |
---|---|---|
CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/o:redhat:enterprise_linux:9 |
Wed, 11 Sep 2024 13:30:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Metrics |
ssvc
|
Thu, 08 Aug 2024 23:00:00 +0000
Type | Values Removed | Values Added |
---|---|---|
First Time appeared |
Redhat
Redhat enterprise Linux |
|
CPEs | cpe:/a:redhat:enterprise_linux:8::nfv cpe:/o:redhat:enterprise_linux:8 |
|
Vendors & Products |
Redhat
Redhat enterprise Linux |
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-06-21T10:18:04.335Z
Updated: 2024-11-05T09:22:02.669Z
Reserved: 2024-06-21T10:13:16.276Z
Link: CVE-2024-31076
Vulnrichment
Updated: 2024-08-02T01:46:03.929Z
NVD
Status : Awaiting Analysis
Published: 2024-06-21T11:15:09.673
Modified: 2024-11-21T09:12:48.140
Link: CVE-2024-31076
Redhat