CVE-2026-63944
CVE-2026-63944CVE-2026-63944
Description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: fix UAF in hci_le_create_cis_sync
hci_le_create_cis_sync() dereferences conn->conn_timeout after releasing
both rcu_read_lock() and hci_dev_lock(hdev). The conn pointer was
obtained from an RCU-protected iteration over hdev->conn_hash.list and
is not valid once these locks are dropped. A concurrent disconnect can
free the hci_conn between the unlock and the dereference, causing a
use-after-free read.
The cancellation mechanism in hci_conn_del() cannot prevent this because
hci_le_create_cis_pending() queues hci_create_cis_sync with data=NULL:
hci_cmd_sync_queue(hdev, hci_create_cis_sync, NULL, NULL);
While hci_conn_del() dequeues with data=conn:
hci_cmd_sync_dequeue(hdev, NULL, conn, NULL);
Since NULL != conn, the lookup in _hci_cmd_sync_lookup_entry() never
matches, and the pending work item is not cancelled.
Fix this by saving conn->conn_timeout into a local variable while the
lo
Scoring
| Last modified | 2026-07-19 |