CVE-2026-89583

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

Bluetooth: eir: Fix OOB read in eir get service data()

eir get service data() walks the advertising data for a Service Data field with a matching UUID. On a mismatch it advances:

eir += dlen; eir len -= dlen;

eir get data() reports dlen as the field's data length, but the field spans dlen + 2 bytes once its length and type bytes count, and more when non-Service-Data fields were skipped to reach it. The pointer lands correctly on the next field. eir len does not, and the shortfall compounds across fields until eir get data() reads the length and type bytes of a "field" past the end of the buffer.

For an ISO broadcast sink that buffer is hcon->le per adv data[], filled from the periodic advertising reports of a remote broadcaster. A PA payload packed with mismatching Service Data fields walks off the array into the rest of struct hci conn. A drifted field that matches the BAA UUID puts those bytes in iso pi(sk)->base, where user space reads them back with getsockopt(BT ISO BASE).

Recompute eir len from the end of the buffer each iteration.