In the Linux kernel, the following vulnerability has been resolved:
irqchip/gic-v5: Immediately exec priority drop following activate
With GICv5 an interrupt of equal or lower priority cannot be signalled
until there has been a priority drop. This is done via the GIC CDEOI
system instruction. Once this has been executed, the hardware is able
to signal the next interrupt if there is one.
As all interrupts are programmed to have the same priority, no new
interrupts can be signalled until the priority drop has happened. This
can cause issues when, for example, an interrupt remains active while
a long running process takes place, such as when injecting a physical
interrupt into a guest VM in software.
The GICv5 driver has so far done the priority drop as part of
irq_eoi(), i.e., at the same time as deactivating the interrupt. This
means that any long running process (or VM) could block incoming
interrupts, effectively causing a denial of service for all other
interrupts.
Rather than doing the EOI as part of irq_eoi() (which the name would
suggest would be a good place for it), move it to happen immediately
after acknowledging an interrupt in the main GICv5 interrupt
handler. The deactivation of interrupts (GIC CDDI) remains implemented
as part of irq_eoi(), which means that the same interrupt cannot be
signalled a second time until deactivated by software.
irqchip/gic-v5: Immediately exec priority drop following activate
With GICv5 an interrupt of equal or lower priority cannot be signalled
until there has been a priority drop. This is done via the GIC CDEOI
system instruction. Once this has been executed, the hardware is able
to signal the next interrupt if there is one.
As all interrupts are programmed to have the same priority, no new
interrupts can be signalled until the priority drop has happened. This
can cause issues when, for example, an interrupt remains active while
a long running process takes place, such as when injecting a physical
interrupt into a guest VM in software.
The GICv5 driver has so far done the priority drop as part of
irq_eoi(), i.e., at the same time as deactivating the interrupt. This
means that any long running process (or VM) could block incoming
interrupts, effectively causing a denial of service for all other
interrupts.
Rather than doing the EOI as part of irq_eoi() (which the name would
suggest would be a good place for it), move it to happen immediately
after acknowledging an interrupt in the main GICv5 interrupt
handler. The deactivation of interrupts (GIC CDDI) remains implemented
as part of irq_eoi(), which means that the same interrupt cannot be
signalled a second time until deactivated by software.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 23 Oct 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux linux
|
|
| Weaknesses | CWE-760 | |
| Vendors & Products |
Linux linux
|
Fri, 23 Oct 2026 12:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v5: Immediately exec priority drop following activate With GICv5 an interrupt of equal or lower priority cannot be signalled until there has been a priority drop. This is done via the GIC CDEOI system instruction. Once this has been executed, the hardware is able to signal the next interrupt if there is one. As all interrupts are programmed to have the same priority, no new interrupts can be signalled until the priority drop has happened. This can cause issues when, for example, an interrupt remains active while a long running process takes place, such as when injecting a physical interrupt into a guest VM in software. The GICv5 driver has so far done the priority drop as part of irq_eoi(), i.e., at the same time as deactivating the interrupt. This means that any long running process (or VM) could block incoming interrupts, effectively causing a denial of service for all other interrupts. Rather than doing the EOI as part of irq_eoi() (which the name would suggest would be a good place for it), move it to happen immediately after acknowledging an interrupt in the main GICv5 interrupt handler. The deactivation of interrupts (GIC CDDI) remains implemented as part of irq_eoi(), which means that the same interrupt cannot be signalled a second time until deactivated by software. | |
| Title | irqchip/gic-v5: Immediately exec priority drop following activate | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-23T11:37:25.121Z
Reserved: 2026-09-25T10:25:14.377Z
Link: CVE-2026-98878
No data.
Status : Received
Published: 2026-10-23T12:18:21.330
Modified: 2026-10-23T12:18:21.330
Link: CVE-2026-98878
No data.
OpenCVE Enrichment
Updated: 2026-10-23T14:30:13Z
Weaknesses
No weakness.