Linux Kernel EUVD-2026-55510

The GVE (Google Virtual Ethernet) driver is the paravirtualized NIC driver used by Google Compute Engine (GCE) Linux VM instances. It uses a descriptor-ring model where the guest kernel must pre-post Rx buffers to hardware for incoming packets. Under extreme memory pressure, kernel page allocations for these buffers can fail. The bug is a livelock in the NAPI polling subsystem: NAPI is only scheduled when Rx completions arrive, completions only arrive when the hardware has descriptors, and descriptors can only be refilled when NAPI runs - forming a deadlock once the ring drains below the critical threshold. The fix introduces a per-queue starvation recovery timer that force-reschedules NAPI until the buffer level recovers. The threshold of 32 is derived from the maximum number of descriptors (up to 19) a single maximum-sized Receive Segment Coalescing (RSC) packet can consume. Affected CPEs include cpe:2.3:a:linux:linux covering kernel versions from the introduction of this code path at commit 9b8dd5e5ea48. The CWE is not assigned, but the root cause class is a missing recovery path for resource exhaustion (analogous to CWE-400, Uncontrolled Resource Consumption, or CWE-834, Excessive Iteration), not memory corruption or privilege escalation. Note: the input tags this as 'Information Disclosure,' which is inconsistent with the CVSS vector (C:N/I:N/A:H) and the description - this appears to be a metadata tagging error; the vulnerability is purely a denial-of-service condition.