Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-06-09T00:00:00 kernel: tun: free page on short-frame rejection in tun_xdp_one() 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-763

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.

A flaw was found in the Linux kernel. A local attacker with access to the tun/tap device can exploit this vulnerability. By sending network frames shorter than the expected header length, the system fails to free allocated memory pages, leading to memory leaks. This can exhaust system memory, resulting in a denial of service (DoS) and causing the system to crash.

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Out of support scope kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Not affected kernel Red Hat Enterprise Linux 9 Not affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-46321 https://nvd.nist.gov/vuln/detail/CVE-2026-46321 https://lore.kernel.org/linux-cve-announce/2026060925-CVE-2026-46321-8e46@gregkh/T