CVE-2026-93830

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the stmmac network driver for xgmac2 devices where enabling the RX Buffer Unavailable (RBUE) interrupt can trigger a MAC interrupt storm during periods of heavy RX pressure. This occurs because the DMA continuously fires the RBUE interrupt when it runs out of RX descriptors until the software refills the ring. The RBUE interrupt is redundant as the normal RX completion interrupt (RIE) already triggers NAPI to process descriptors and refill the ring. In observed cases on Agilex5, the MAC interrupt fired over 1.8 billion times compared to approximately 2.6 million actual RX completions. Furthermore, RBUE does not provide Out-of-Memory (OOM) recovery; if the page pool is exhausted, the stmmac rx refill() function cannot advance the DMA tail pointer, leading to a continuous interrupt storm without forward progress.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.