CVE-2026-68411wifi: mac80211_hwsim: clamp virtio RX length before skb_put

Official description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211_hwsim: clamp virtio RX length before skb_put hwsim_virtio_rx_work() passes the virtqueue used-ring length reported by the device straight to skb_put() on a fixed-size receive skb. A backend reporting a length larger than the skb tailroom drives skb_put() past the buffer end and hits skb_over_panic() -- a host-triggerable guest panic (denial of service). Clamp the length to the skb's available room before skb_put(). A conforming device never reports more than the posted buffer size, so valid frames are unaffected; a truncated over-report then fails the length/header checks in hwsim_virtio_handle_cmd() and is dropped, so truncating rather than dropping here cannot be turned into a parsing problem.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/7f9d678b870fca8eaf1d46fa915cba0b1d5b387a
• https://git.kernel.org/stable/c/909573d6a9b67354fc0515952574564e7c909c62
• https://git.kernel.org/stable/c/5779e4a33e1666ddfeba43e96e29c4a9e5254ff0
• https://git.kernel.org/stable/c/82c5a30a66e2a7337d99476c67d6fc1a99c4250e
• https://git.kernel.org/stable/c/fade308845c89f784da8a6780c1e77258488f1b6
• https://git.kernel.org/stable/c/6dc76371a9a360c29de00df5b11563102d9d675a
• https://git.kernel.org/stable/c/99dc05c75acc3c8cde8d89c5371f4b569de5ac62
• https://git.kernel.org/stable/c/10a2b430f8f06ae14b9590b6f6faa6b588ef0654