CVE-2026-99013CVE-2026-99013

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: Reject concurrent BIS listener setup iso_sock_listen() drops the socket lock before calling iso_listen_bis() to preserve the hdev->lock ordering. Two concurrent listen() calls on the same broadcast socket can therefore both observe BT_BOUND. Caller A can attach connA and release the locks, then caller B can acquire them and attach connB before A publishes BT_LISTEN. __iso_chan_add() checks whether connB already has a socket, but not whether the socket already has a connection. The second attachment overwrites iso_pi(sk)->conn, leaking the connA reference and leaving connA->sk intact. Socket teardown follows connB, so later events on connA can cause a stale socket access. Recheck BT_BOUND and require iso_pi(sk)->conn to be NULL after taking both the HCI device and socket locks in iso_listen_bis(). The connection check also covers the interval between attachment and publication of BT_LISTEN. Reject a