CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's handling of the bcmgenet network driver, specifically when RBUF_EEE_EN and RBUF_PM_EN are enabled, which disrupts the RX path on GENET hardware, leading to a halt in RX traffic while the link remains active. This can result in packet loss and potential system crashes, particularly on devices like the Raspberry Pi 4B and certain Broadcom boards. Organizations utilizing affected Linux kernel versions on devices with bcmgenet hardware should prioritize patching this critical vulnerability to maintain network reliability and system stability.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: net: bcmgenet: keep RBUF EEE/PM disabled Setting RBUF_EEE_EN | RBUF_PM_EN in RBUF_ENERGY_CTRL breaks the RX path on GENET hardware once MAC EEE becomes active. RX traffic stops flowing while the link stays up and the usual descriptor/RX error counters remain quiet. In that state the MAC still accepts frames (rbuf_ovflow_cnt keeps climbing) but RBUF no longer forwards them to DMA, so rx_packets is no longer incremented at the netdev level. On some boards the corruption ends up as a paging fault in skb_release_data via bcmgenet_rx_poll on an LPI exit. Reproduced on Pi 4B (BCM2711 + BCM54213PE) and confirmed by Florian Fainelli on an internal Broadcom 4908-family board with the same crash signature. RBUF_PM_EN is not publicly documented. This shows up more often now that phy_support_eee() enables EEE by default, but it also affects older kernels as soon as TX LPI is turned on via ethtool, so it is not specific to recent changes. Always clear RBUF_EEE_EN | RBUF_PM_EN in bcmgenet_eee_enable_set so the bits stay off across resets. UMAC and TBUF setup is left alone so TX-side EEE keeps working.
Related CVEs
Other vulnerabilities affecting the same vendor(s)