CVE-2026-64405

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: Fix null ptr deref in hci_abort_conn() hci_abort_conn() read hci_skb_event(hdev->sent_cmd) when a connection was pending, but hdev->sent_cmd can be NULL while req_status is still HCI_REQ_PEND, leading to a NULL pointer dereference and a general protection fault from the hci_rx_work() receive path. Instead of inspecting hdev->sent_cmd, track the in-flight create connection command with a new per-connection HCI_CONN_CREATE flag and route all cancellation through hci_cancel_connect_sync(), which dispatches to a dedicated per-type cancel function. The create command is in exactly one of two states: still queued, or in flight. The cancel function holds cmd_sync_work_lock across the whole decision: the worker takes this lock to dequeue every entry, so while it is held a queued command cannot start running and an in-flight command cannot complete and let the next command become pending. This keeps the flag test and hci_cmd_sync_cancel() atomic with respect to the worker, so a queued command is simply dequeued, and an in-flight command owned by this connection is cancelled without the risk of cancelling an unrelated command that became pending in the meantime. CIS uses the same flag mechanism via HCI_CONN_CREATE_CIS but cannot be dequeued per-connection. hci_acl_create_conn_sync() and hci_le_create_conn_sync() clear HCI_CONN_CREATE after the create command completes, but the command status handler can free conn via hci_conn_del() (for example when the controller rejects the connection) while the worker is still blocked on the connection complete event. Hold a reference on conn across the create command so the flag can be cleared without a use-after-free.

Package Linux Kernel
Published 2026-07-25
Last modified 2026-07-25
Patch available
Yes

Affected versions

Linux kernel versions 6.1.83, 6.4.16, 6.5.3, 6.6 and later are affected. Fixed in 6.1.118, 6.6.145, 6.12.97, 6.18.39, 7.1.4, 7.2-rc3 and their respective stable series.

Affected from
≥ 6.1.83 ≥ 6.4.16 ≥ 6.5.3 ≥ 6.6
Fixed in
✓ 6.1.118 6.1.x ✓ 6.6.145 6.6.x ✓ 6.12.97 6.12.x ✓ 6.18.39 6.18.x ✓ 7.1.4 7.1.x ✓ 7.2-rc3

Frequently asked questions

  • What is CVE-2026-64405?

    CVE-2026-64405 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.1.83 onward and has been patched in 6.1.118, 6.6.145, 6.12.97 and others. CVE-2026-64405 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2026-64405?

    Yes. CVE-2026-64405 has been patched. Fixed versions include 6.1.118, 6.6.145, 6.12.97 and others. If you are running Linux kernel 6.1.83 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-64405 actively exploited?

    No. CVE-2026-64405 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.