Broadcom bnx2x NIC Firmware Panic Fix for Oversized GSO Packets

Key Information Vulnerability Description - When the bnx2x network card receives a GSO (Generic Segmentation Offload) packet with exceeding the hardware limit (approximately 9700 bytes), it triggers a firmware error, causing the network card to fail. Root Cause - The issue occurred on a PowerPC system where Open vSwitch forwarded a packet originating from an ibmveth device. - The ibmveth driver allows very large packet transmissions (up to 64KB) but does not support any form of message size negotiation/MSS negotiation. This can result in large MSS packets appearing in environments that do not support them. Mitigation Measures - Prevent from exceeding the maximum packet size (9700 bytes), thereby disabling GSO. - Move error recovery logic in the forwarding path to the IP layer or lower to address the issue of large MSS packets. Code Changes - Modified the function to disable GSO when exceeds 9200 bytes. Discussion Points - Some suggested using to limit GSO packet size, but this approach does not work in the forwarding path. - Software recovery logic needs to be added in the network transmission path to handle large MSS packets in the forwarding path. This screenshot describes a firmware error caused by GSO packet size issues in specific hardware and configuration environments, along with the corresponding fix.

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Broadcom bnx2x NIC Firmware Panic Fix for Oversized GSO Packets