CVE-2026-98457

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: validate frame length before control and FCS access

l2cap_data_rcv() unpacks either a two-byte or four-byte control field

without first ensuring that it is present. A short ERTM or streaming-mode

frame can therefore cause an out-of-bounds read.

There is a second short-frame case when CRC16 is enabled. After the

control field is pulled, l2cap_check_fcs() subtracts two from skb->len

without checking it. If fewer than two bytes remain, the subtraction

wraps; skb_trim() leaves the buffer unchanged and the subsequent FCS

load reads past the logical end of the frame.

Validate that the frame contains both its control field and, when

enabled, its FCS before either field is accessed.