CVE-2026-68299

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

vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets

vmxnet3_get_hdr_len() assumes gdesc->rcd.v4/v6/tcp always describe the

outer header, but for a Geneve-encapsulated packet the device can set

them based on the inner header instead, signalled by the

VMXNET3_RCD_HDR_INNER_SHIFT bit in the completion descriptor. Since the

function never skips the outer encapsulation, this mismatch triggers:

- BUG_ON(hdr.ipv4->protocol != IPPROTO_TCP), because the outer

protocol is UDP (Geneve), not TCP.

- BUG_ON(hdr.eth->h_proto != ...), when the tunnel's outer and inner

IP versions differ (e.g. outer IPv6/inner IPv4 or vice versa).

Check VMXNET3_RCD_HDR_INNER_SHIFT up front and bail out, since the

function cannot locate the inner header it would need to parse. Also

convert the remaining BUG_ON()s in this function to return 0

defensively.