CVE-2026-46321

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

tun: free page on short-frame rejection in tun_xdp_one()

tun_xdp_one() returns -EINVAL on a frame shorter than ETH_HLEN without

freeing the page that vhost_net_build_xdp() allocated for it.

tun_sendmsg() discards that -EINVAL and still returns total_len, so

vhost_tx_batch() takes the success path and never frees the page; each

short frame in a batch leaks one page-frag chunk.

A local process that can open /dev/net/tun and /dev/vhost-net can hit

this path: it attaches a tun/tap device as the vhost-net backend and

feeds TX descriptors whose length minus the virtio-net header is below

ETH_HLEN. Each kick leaks the page-frag chunks for that batch, and a

tight submission loop exhausts host memory and triggers an OOM panic.

Free the page before returning -EINVAL, matching the XDP-program error

path in the same function.