In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix heap buffer overflow in rtw_cfg80211_set_wpa_ie

In the Linux kernel, the following vulnerability has been resolved:

staging: rtl8723bs: fix heap buffer overflow in rtw_cfg80211_set_wpa_ie()

supplicant_ie is a 256-byte array in struct security_priv. The WPA and
WPA2 IE copy paths use:

 1memcpy(padapter->securitypriv.supplicant_ie, &pwpa[0], wpa_ielen + 2);

where wpa_ielen is the raw IE length field (u8, 0-255). When a local user
supplies a connect request via nl80211 with a crafted WPA IE of length 255,
wpa_ielen + 2 equals 257, overflowing the 256-byte buffer by one byte into
the adjacent last_mic_err_time field.

rtw_parse_wpa_ie() does not prevent this: its length consistency check
compares *(wpa_ie+1) against (u8)(wpa_ie_len-2), which is (u8)(255) == 255
when wpa_ie_len = 257, so the check passes silently.

Add explicit bounds checks for both the WPA and WPA2 paths before the
memcpy, rejecting any IE whose total size (wpa_ielen + 2) exceeds the
supplicant_ie buffer.