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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- EPSS
- 0.13% probability · 3th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/0a6f46a9332ad6958992d64d3b3a81a80b2ca940Patch
- https://git.kernel.org/stable/c/0e8211fcf9426f5adddf32516ba0f400ceb9544dPatch
- https://git.kernel.org/stable/c/37a1c268c2c8090bf4dc552d732bd23ba36f8eb0Patch
- https://git.kernel.org/stable/c/5b34f9e4fe2f203724a6e893d6df0316b9670057Patch
- https://git.kernel.org/stable/c/69863ff2720a0e9871f1a5710f2a33a94217fee0Patch
- https://git.kernel.org/stable/c/98c67be9eb9de72465a071949e84a3cdb8fab5a3Patch
- https://git.kernel.org/stable/c/e915445942af6dcea628bf66d6241641201a0c41Patch
- https://git.kernel.org/stable/c/f4feb1e20058e407cb00f45aff47f5b7e19a6bbfPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.