CVE-2026-43031net: xilinx: axienet: Fix BQL accounting for multi-BD TX packets

Official description

In the Linux kernel, the following vulnerability has been resolved: net: xilinx: axienet: Fix BQL accounting for multi-BD TX packets When a TX packet spans multiple buffer descriptors (scatter-gather), axienet_free_tx_chain sums the per-BD actual length from descriptor status into a caller-provided accumulator. That sum is reset on each NAPI poll. If the BDs for a single packet complete across different polls, the earlier bytes are lost and never credited to BQL. This causes BQL to think bytes are permanently in-flight, eventually stalling the TX queue. The SKB pointer is stored only on the last BD of a packet. When that BD completes, use skb->len for the byte count instead of summing per-BD status lengths. This matches netdev_sent_queue(), which debits skb->len, and naturally survives across polls because no partial packet contributes to the accumulator.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/2a0323a913109b52bfc9f5ea7b92a1b249e07d3e
• https://git.kernel.org/stable/c/3c3a6b9020c01fde7b22e8550105de0b59904f61
• https://git.kernel.org/stable/c/d1978d03e86785872871bff9c2623174b10740de