staging: rtl8723bs: fix out-of-bounds read in rtw_get_ie() parser

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix out-of-bounds read in rtw_get_ie() parser The Information Element (IE) parser rtw_get_ie() trusted the length byte of each IE without validating that the IE body (len bytes after the 2-byte header) fits inside the remaining frame buffer. A malformed frame can advertise an IE length larger than the available data, causing the parser to increment its pointer beyond the buffer end. This results in out-of-bounds reads or, depending on the pattern, an infinite loop. Fix by validating that (offset + 2 + len) does not exceed the limit before accepting the IE or advancing to the next element. This prevents OOB reads and ensures the parser terminates safely on malformed frames.