What’s Vulnerable › Vulnerabilities

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

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-10 · updated 2026-08-19

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 products

• Linux kernel: 5.7 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

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

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