staging: rtl8723bs: fix OOB reads in IE loops in issue_assocreq() and join_cmd_hdl()

staging: rtl8723bs: fix OOB reads in IE loops in issue_assocreq() and join_cmd_hdl()

Two IE parsing loops are missing the header bounds checks before they
dereference pIE->length:

 - issue_assocreq() walks pmlmeinfo->network.ies to build the
   association request. If the stored IE data ends with only an
   element_id byte and no length byte, pIE->length is read one byte
   past the end of the buffer.

 - join_cmd_hdl() walks pnetwork->ies during station join and has
   the same problem under the same conditions.

Both buffers are filled from AP beacon and probe-response frames, so a
malicious AP that sends a truncated final IE can trigger the issue.

Apply the two-guard pattern established in update_beacon_info():
  1. Break if fewer than sizeof(*pIE) bytes remain.
  2. Break if the IE's declared data extends past the buffer end.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Reviewed-by: Luka Gejak <luka.gejak@linux.dev>
Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
Link: https://patch.msgid.link/20260522004531.1038924-3-hossu.alexandru@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>