CVE-2026-74536

/// Technical description

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

Bluetooth: ISO: fix leaking sk after socket release

iso_sock_kill() tests !sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket ||

sock_flag(sk, SOCK_DEAD) for early return, but this is always true since

sock_orphan(sk) sets SOCK_DEAD, so the sk reference released by socket

always leaks, iso_sock_destruct is never called.

The socket reference also leaks when __iso_sock_close() does not set

SOCK_ZAPPED, since iso_conn_del() does not call iso_sock_kill() after

zapping.

Fix by replacing SOCK_DEAD by BT_SK_KILLED flag that is not used for

something else, and lock_sock to ensure iso_sock_kill() puts sk only

after socket release only once. Release and iso_conn_del may run

concurrently. Call iso_sock_kill() from iso_conn_del() to clean sk up

after zapping.

Remove call to iso_sock_kill() from iso_sock_close(), as it's generally

no-op there.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References