Bluetooth: eir: Fix OOB read in eir_get_service_data()

Overview

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.

Affected

• Linux >= 8f9ae5b3ae80f168a6224529e3787f4fb27f299a < b6902adf81ea2ce14b1040dd97b6980050a8125a
• Linux >= 8f9ae5b3ae80f168a6224529e3787f4fb27f299a < 1a28aae7f1fc8c06c0d02f153541be4fc7bacb74
• Linux >= 8f9ae5b3ae80f168a6224529e3787f4fb27f299a < 815fc98c227a78cbd93d4c29f2833705b7c2bc0f
• Linux >= 8f9ae5b3ae80f168a6224529e3787f4fb27f299a < c21fa79301d7d6ac0a4ec6c51e8ba10beaa08c50
• Linux >= 8f9ae5b3ae80f168a6224529e3787f4fb27f299a < bb56e97bd67614238c1c0a4084704ccadbb875b4
• Linux >= 8f9ae5b3ae80f168a6224529e3787f4fb27f299a < 4beb198bc59b242404a47c21990bc84165052c8a
• Linux 5.19

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Vendor advisories

• Red Hat VEX · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-14 · vex