Bug 2513473 (CVE-2026-68411)

Summary: CVE-2026-68411 kernel: wifi: mac80211_hwsim: clamp virtio RX length before skb_put
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's mac80211_hwsim component. A malicious backend device could report an oversized receive length to the `hwsim_virtio_rx_work()` function. This could cause the system to write past the end of a buffer, leading to a kernel panic and a denial of service (DoS) for the guest system.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-10 12:39:20 UTC 
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.
Comment 1 Mauro Matteo Cascella 2026-08-11 08:18:07 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081050-CVE-2026-68411-8001@gregkh/T