CVE-2026-31497

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

Bluetooth: btusb: clamp SCO altsetting table indices

btusbwork() maps the number of active SCO links to USB alternate settings through a three-entry lookup table when CVSD traffic uses transparent voice settings. The lookup currently indexes alts[] with data->sconum - 1 without first constraining sco_num to the number of available table entries.

While the table only defines alternate settings for up to three SCO links, data->sconum comes from hciconn_num() and is used directly. Cap the lookup to the last table entry before indexing it so the driver keeps selecting the highest supported alternate setting without reading past alts[].