staging: rtl8723bs: fix OOB reads in is_ap_in_tkip() IE loop

staging: rtl8723bs: fix OOB reads in is_ap_in_tkip() IE loop

The loop in is_ap_in_tkip() iterates over IEs without verifying that
enough bytes remain before dereferencing the IE header or its payload:

- pIE->element_id and pIE->length are read without checking that
  i + sizeof(*pIE) <= ie_length, so a truncated IE at the end of the
  buffer causes an OOB read.

- For WLAN_EID_VENDOR_SPECIFIC the code compares pIE->data + 12,
  which requires pIE->length >= 16.  For WLAN_EID_RSN it compares
  pIE->data + 8, requiring pIE->length >= 12.  Neither requirement
  is checked.

Add the missing IE header and payload bounds checks and guard each
data access with an explicit pIE->length minimum, matching the
pattern established in update_beacon_info().

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/20260522004531.1038924-7-hossu.alexandru@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>