Overview
About vulnerability
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.
Details
- Affected product:
- Debian 10 ELS
- Affected packages:
- linux @ 4.19.0