CVE-2026-64430
In the Linux kernel, the following vulnerability has been resolved:
NTB: epf: Avoid calling pci_irq_vector() from hardirq context
ntb_epf_vec_isr() calls pci_irq_vector() in hardirq context to derive
the vector number. pci_irq_vector() calls msi_get_virq() that takes a
mutex and can therefore trigger "scheduling while atomic" splats:
BUG: scheduling while atomic: kworker/u33:0/55/0x00010001
...
Call trace:
...
schedule+0x38/0x110
schedule_preempt_disabled+0x28/0x50
__mutex_lock.constprop.0+0x848/0x908
__mutex_lock_slowpath+0x18/0x30
mutex_lock+0x4c/0x60
msi_domain_get_virq+0xe8/0x138
pci_irq_vector+0x2c/0x60
ntb_epf_vec_isr+0x28/0x120 [ntb_hw_epf]
__handle_irq_event_percpu+0x70/0x3a8
handle_irq_event+0x48/0x100
handle_edge_irq+0x100/0x1c8
...
Cache the Linux IRQ number for vector 0 when vectors are allocated and
use it as a base in the ISR. Running the ISR in a threaded IRQ handler
would also avoid the problem, but that would be unnecessary here.
CSIRTS triage
- What
- An issue exists with calling pci_irq_vector() from hardirq context.
- Who is affected
- Deployments using NTB may be affected.
- Urgency
- Remediation urgency is unclear due to unknown severity and exploitation status.
- Action
- Monitor for updates regarding this issue.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.49% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 39% of all EPSS-scored CVEs.
Advisory coverage (2)
External references
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