Linux kernel (drivers/vfio/pci): A failed interrupt-context allocation while enabling INTx leaks the IRQ name string.

Impact

A failed interrupt-context allocation while enabling INTx leaks the IRQ name string. Individually trivial, but a tenant can drive the failing path repeatedly, and unreclaimable kernel allocations on a shared node are a slow noisy-neighbour outage that eventually reaches every other tenant.

Who can reach it

A tenant holding a vfio-pci device fd calling VFIO_DEVICE_SET_IRQS to enable INTx while the interrupt-context allocation fails. Requires memory pressure to make the allocation fail, so this is an OOM-adjacent amplifier rather than a clean standalone primitive. No host root.

What to do

Update to 5.15.168, 6.1.113, or 6.6.33 or later. Interim control: cap tenant memory with cgroups so they cannot easily drive the host into the allocation-failure regime.

References