In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: cyw: fix heap overflow on a short auth frame
brcmf_notify_auth_frame_rx() takes the frame length from the firmware
event and copies the frame body with the management header offset
subtracted:
u32 mgmt_frame_len = e->datalen – sizeof(struct brcmf_rx_mgmt_data);
…
memcpy(&mgmt_frame->u, frame,
mgmt_frame_len – offsetof(struct ieee80211_mgmt, u));
The only length check is e->datalen >= sizeof(*rxframe), so mgmt_frame_len
can be anything from 0 up. offsetof(struct ieee80211_mgmt, u) is 24. When
mgmt_frame_len is below that, the subtraction wraps as an unsigned value to
a huge length. The memcpy then runs far past the kzalloc’d buffer. A
malicious or malfunctioning AP can make the frame short during the
external SAE auth exchange, so this is a remotely triggered heap overflow.
Reject frames shorter than the management header offset before the copy.
