CVE-2026-64405 Details
Description
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.
A null pointer dereference vulnerability has been identified in the Bluetooth subsystem of the Linux kernel, specifically within the handling of HCI (Host Controller Interface) connections. This issue arises in the 'hci_abort_conn()' function, where it attempts to read the 'sent_cmd' field of the 'hdev' (HCI device) structure. If a connection is pending, 'sent_cmd' can be NULL while the request status is still marked as pending, leading to a null pointer dereference. This flaw causes a general protection fault in the HCI receive path, disrupting normal Bluetooth operations.
The vulnerability has been addressed by modifying the connection handling logic. The HCI connection creation process now includes a dedicated flag to track the status of in-flight commands, ensuring that cancellation requests are properly managed without interfering with unrelated connection operations. Users should apply the latest patches available in the Linux kernel stable tree to mitigate this issue.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/12917f591cea1af36087dba5b9ec888652f0b42a | kernel.org | Patch |
| https://git.kernel.org/stable/c/61701912c58a05f6a043f097cc177a964abef348 | kernel.org | Patch |
| https://git.kernel.org/stable/c/70c397b62ee015e19b3924d9da741c8dda017819 | kernel.org | Patch |
| https://git.kernel.org/stable/c/83b22d7f7c384564fa42c3cf19bec715c693d7a2 | kernel.org | Patch |
| https://git.kernel.org/stable/c/903227b6168bb99fd57d4e3c9c1b5014986198e0 | kernel.org | Patch |
| https://git.kernel.org/stable/c/b42cb640a0493d16b61ddd267420274be15efdc1 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-476 | NULL Pointer Dereference | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 6.1.83, < 6.1.118 >= 6.4.16, < 6.5 >= 6.5.3, < 6.6.145 >= 6.7, < 6.12.97 >= 6.13, < 6.18.39 >= 6.19, < 7.1.4 7.2 rc1 7.2 rc2 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 4, 2026 | Initial Analysis | [email protected] |
| Aug 17, 2026 | CVE Modified | kernel.org |
| Jul 25, 2026 | New CVE Received | kernel.org |