UBUNTU-CVE-2026-89907: High severity ubuntu/linux-hwe-edge vulnerability

In the Linux kernel, the following vulnerability has been resolved: LoongArch: KVM: Validate MSI data before routing it to EIOINTC pchmsisetirq() passes e->msi.data straight into eiointcsetirq() as the irq number. The MSI data comes from userspace, that either via a KVMIRQROUTINGMSI entry set with KVMSETGSIROUTING (used by irqfd and KVMIRQLINE) or directly via KVMSIGNALMSI, and is never checked against EIOINTCIRQS. eiointcsetirq() uses the value with setbit()/clearbit() on the 256-bit isr bitmap, eiointcupdateirq() then indexes swcoremap[] and the per-cpu coreisr/swcoreisr bitmaps with it. Therefore a data value >= 256 reads and writes memory past the end of those arrays, i.e. any process holding a VM fd can corrupt kernel memory beyond the allocation of loongarcheiointc. Reject MSI data that doesn't fit in the EIOINTC irq space. The DMSINTC path is unaffected as it decodes the vector from the address and masks it.