CVE-2026-74536Bluetooth: ISO: fix leaking sk after socket release

Official 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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/96ed3c772c08e7a91c399567f412618e43231023
• https://git.kernel.org/stable/c/e76a0ae6542ae43241b2147bacf4990e7ae5316a
• https://git.kernel.org/stable/c/e30e5ca63c8fbe3cd505fbb419bb547760cda633
• https://git.kernel.org/stable/c/ce57442a379212fe3fda59c9437ee8217eceb5b1