NVD Vulnerability Detail
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CVE-2026-46321
Summary

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.

Publication Date June 9, 2026, 10:16 p.m.
Registration Date June 10, 2026, 4:15 a.m.
Last Update June 14, 2026, 3:16 p.m.
CVSS3.1 : HIGH
スコア 7.1
Vector CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
攻撃元区分(AV) ローカル
攻撃条件の複雑さ(AC)
攻撃に必要な特権レベル(PR) 不要
利用者の関与(UI) 不要
影響の想定範囲(S) 変更あり
機密性への影響(C) なし
完全性への影響(I) なし
可用性への影響(A)
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