CVE-2026-90255: Bluetooth: hci_conn: fix the SCO setup context lifetime

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-17 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: fix the SCO setup context lifetime hci_setup_sync() queues a conn_handle_t with a NULL destroy callback, so the context is only freed if hci_enhanced_setup_sync() actually runs. An entry that is cancelled instead is leaked, as _hci_cmd_sync_cancel_entry() does not release entry->data when there is no destroy callback, and hci_cmd_sync_clear() cancels every pending entry when the controller is unregistered. The context also stores a bare hci_conn pointer, so the connection can be freed while the work is queued. The dequeue in hci_conn_del() does not cover it either, as it matches on entry->data == conn and entry->data is the wrapper here. Same problem as commit 2f5d635ad590 ("Bluetooth: hci_sync: hold conn in hci_connect_acl/le_sync() callbacks"). Hold the connection and release both from a destroy callback. The submission failure path drops both, since hci_cmd_sync_submit() does not call the destroy callback when it fails to queue.

Affected products

Linux kernel: 6.1 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

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