In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix OOB read in update_beacon_info() IE loop
The IE parsing loop in update_beacon_info() advances by (pIE->length + 2) each iteration but only guards on i < len. When a malicious AP sends a Beacon whose last IE has only one byte remaining in the frame (the element_id byte lands at len-1), the loop reads pIE->length from one byte past the allocated receive buffer.
Additionally, even when the header bytes are in bounds, pIE->length itself can extend the data window beyond len, passing a truncated IE to the handler functions.
Add two guards at the top of the loop body:
- Break if fewer than sizeof(*pIE) bytes remain (cant read header).
- Break if the IEs declared data extends past len.
Also replace i += (pIE->length + 2) with i += sizeof(*pIE) + pIE->length for consistency with the sizeof(*pIE) guards added above.
References
- https://git.kernel.org/stable/c/5e8db4cff5b45c7c4edc8ae3f302027c3bb32b25
- https://git.kernel.org/stable/c/69f174a0673b6b7a29b851adb60bc450cdc0ecc4
- https://git.kernel.org/stable/c/6dd5e8c3011ebabf417257d7f07901a7c4311539
- https://git.kernel.org/stable/c/9193c34f75fd9e1ea8a590d7cced464c3380dc29
- https://git.kernel.org/stable/c/b5cc2f999927f69723ca53f1f2a3aa37dbeda907
- https://git.kernel.org/stable/c/bd953d52d587d42365e399b96c52dbdb13032070
- https://git.kernel.org/stable/c/ed51de4a86e173c3b0ef78e039c2e49e08b11f16