The Linux kernel NTB transport vulnerability (CVE-2026-80987) arises from improper handling of oversized TX buffers in the ntb_process_tx() function. When an oversized buffer is processed, the function calls tx_handler() with a NULL data pointer and returns success, causing ntb_netdev to neither free the socket buffer (skb) in its completion callback nor follow the error path for enqueue failures. This results in a memory leak. The patch rejects oversized buffers in ntb_transport_tx_enqueue() before queue acquisition, returning -EMSGSIZE and allowing the caller to retain ownership and free the buffer appropriately.

The vulnerability causes a memory leak in the Linux kernel NTB transport subsystem due to improper handling of oversized transmit buffers. This could potentially degrade system stability or performance over time but does not indicate direct code execution or privilege escalation based on the provided data.

No explicit vendor advisory or patch link is provided in the input data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The described fix involves rejecting oversized buffers early to prevent leaks; applying the corresponding kernel update when available is recommended.