Linux EUVD-2026-81738

In the Linux kernel, the following vulnerability has been resolved:

hinic3: Fix skb linearization mismatch and drop skb when skb_checksum_help() failed

Previously, hinic3_send_one_skb() cached the skb fragment count before calling hinic3_tx_offload(). If hinic3_tx_csum() falls back to skb_checksum_help() for unsupported tunnel packets, the skb may be linearized. Continuing to build the TX descriptor with the stale fragment count leads to a descriptor mismatch, which can trigger out-of-bounds DMA reads or IOMMU faults.

Furthermore, the old code ignored the return value of skb_checksum_help(), transmitting corrupted packets with incomplete checksums upon failure.

Fix this by:

1. Moving the hinic3_tx_offload() call before calculating 'num_sge' to

ensure the correct fragment count is used if the SKB is linearized.

1. Propagating skb_checksum_help() errors and returning

HINIC3_TX_OFFLOAD_INVALID to properly drop the skb.