Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath6kl: clamp assoc request/response lengths before subtracting IE offsets
ath6kl_cfg80211_connect_event() subtracts fixed IE offsets from assoc_req_len (-= 4) and assoc_resp_len (-= 6), both u8, with no lower bound. The aggregate check recently added to ath6kl_wmi_connect_event_rx() bounds the declared lengths from above (their sum must fit the received event), but an assoc request/response shorter than its fixed offset still underflows here: the u8 wraps to ~250, and cfg80211_connect_result() / cfg80211_roamed() then treat that wrapped value as the IE length and copy that many bytes out of the small assoc_info buffer to user space via nl80211, disclosing adjacent slab memory.
Clamp both lengths to their offsets before subtracting.
Found by 0sec (https://0sec.ai) using automated source analysis; the missing lower bound is evident from source. Compile-tested.
Details
- Affected product:
- Debian 10 ELS , Debian 11 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.10.259 (+4 more)