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

Vulnerability Description

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.

References

• https://git.kernel.org/stable/c/9829c6e1b2e4180fd18315252ad6faeab6128076
• https://git.kernel.org/stable/c/b977eb31802817f4a37da95bf16bfdaa1eeb5fc2
• https://git.kernel.org/stable/c/30c558447e90935f0de61be181bbcedf75952e00
• https://git.kernel.org/stable/c/a54e2b2db1b7de2e008b4f62eec35aaefcc663c5
• https://git.kernel.org/stable/c/df191dd9f4c7249d98ada55634fa8ac19089b8cb
• https://git.kernel.org/stable/c/c0d93d69e1472ba75b78898979b90a98ba2a2501
• https://git.kernel.org/stable/c/154828bf9559b9c8421fc2f0d7f7f76b3683aaed