CVE-2026-68411: wifi: mac80211_hwsim: clamp virtio RX length before skb_put
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211hwsim: clamp virtio RX length before skbput
hwsimvirtiorxwork() passes the virtqueue used-ring length reported by the device straight to skbput() on a fixed-size receive skb. A backend reporting a length larger than the skb tailroom drives skbput() past the buffer end and hits skboverpanic() -- a host-triggerable guest panic (denial of service).
Clamp the length to the skb's available room before skbput(). 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 hwsimvirtiohandlecmd() and is dropped, so truncating rather than dropping here cannot be turned into a parsing problem.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
In mac80211_hwsim, clamp the virtio RX length to the skb's available room before skb_put() to prevent skb_put() from advancing past the skb tail and triggering skb_over_panic()/guest panic.
Linux kernel (wifi: mac80211_hwsim) virtio RX length handling before skb_put() = Clamp virtio RX length to skb tailroom/available room before calling skb_put()
Event History
Frequently Asked Questions
What is the severity of CVE-2026-68411?
CVE-2026-68411 has a risk rating of 23, indicating a critical vulnerability that could impact system stability and security.
How do I fix CVE-2026-68411?
To fix CVE-2026-68411, update to the latest version of the Linux kernel where the vulnerability has been patched.
What systems are affected by CVE-2026-68411?
CVE-2026-68411 affects systems running vulnerable versions of the Linux kernel that utilize the mac80211_hwsim module.
What is the impact of CVE-2026-68411?
The impact of CVE-2026-68411 could allow an attacker to exploit the vulnerability by sending malicious input, potentially leading to arbitrary code execution or system crashes.
When was CVE-2026-68411 published?
CVE-2026-68411 was published on August 10, 2026.