staging: rtl8723bs: fix WEP length underflow and OOB read in OnAuth()

OnAuth() has two bugs in the shared-key authentication path.

When the Privacy bit is set, rtw_wep_decrypt() is called without
verifying that the frame is long enough to contain a valid WEP IV and
ICV.  Inside rtw_wep_decrypt(), length is computed as:

    length = len - WLAN_HDR_A3_LEN - iv_len

and then passed as (length - 4) to crc32_le().  If len is less than
WLAN_HDR_A3_LEN + iv_len + icv_len (32 bytes), length - 4 is negative
and, after the implicit cast to size_t, causes crc32_le() to read far
beyond the frame buffer.  Add a minimum length check before accessing
the IV field and calling the decryption path.

When processing a seq=3 response, rtw_get_ie() stores the Challenge
Text IE length in ie_len, but the subsequent memcmp() always reads 128
bytes regardless of ie_len.  IEEE 802.11 mandates a challenge text of
exactly 128 bytes; reject any IE whose length field differs, matching
the check already applied to OnAuthClient().

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
Link: https://patch.msgid.link/20260522004605.1039209-1-hossu.alexandru@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions