CVE-2026-46321 PUBLISHED

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

Assigner: Linux
Reserved: 13.05.2026 Published: 09.06.2026 Updated: 09.06.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 049584807f1d797fc3078b68035450a9769eb5c3 to 69863ff2720a0e9871f1a5710f2a33a94217fee0 (excl.)
  • affected from 049584807f1d797fc3078b68035450a9769eb5c3 to 37a1c268c2c8090bf4dc552d732bd23ba36f8eb0 (excl.)
  • affected from 049584807f1d797fc3078b68035450a9769eb5c3 to 98c67be9eb9de72465a071949e84a3cdb8fab5a3 (excl.)
  • affected from 049584807f1d797fc3078b68035450a9769eb5c3 to f4feb1e20058e407cb00f45aff47f5b7e19a6bbf (excl.)
  • Version 32b0aaba5dbc85816898167d9b5d45a22eae82e9 is affected
  • Version 6100e0237204890269e3f934acfc50d35fd6f319 is affected
  • Version 589382f50b4a5d90d16d8bc9dcbc0e927a3e39b2 is affected
  • Version ad6b3f622ccfb4bfedfa53b6ebd91c3d1d04f146 is affected
  • Version d5ad89b7d01ed4e66fd04734fc63d6e78536692a is affected
  • Version a9d1c27e2ee3b0ea5d40c105d6e728fc114470bb is affected
  • Version 8418f55302fa1d2eeb73e16e345167e545c598a5 is affected
  • affected from 5.4.281 to 5.5 (excl.)
  • affected from 5.10.223 to 5.11 (excl.)
  • affected from 5.15.164 to 5.16 (excl.)
  • affected from 6.1.102 to 6.2 (excl.)
  • affected from 6.6.43 to 6.7 (excl.)
  • affected from 6.9.12 to 6.10 (excl.)
  • affected from 6.10.2 to 6.11 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.11 is affected
  • unaffected from 0 to 6.11 (excl.)
  • unaffected from 6.12.93 to 6.12.* (incl.)
  • unaffected from 6.18.35 to 6.18.* (incl.)
  • unaffected from 7.0.12 to 7.0.* (incl.)
  • unaffected from 7.1-rc6 to * (incl.)

References