CVE-2023-53374: Bluetooth: hci_conn: fail SCO/ISO via hci_conn_failed if ACL gone early

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-18 · updated 2026-08-04
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: fail SCO/ISO via hci_conn_failed if ACL gone early Not calling hci_(dis)connect_cfm before deleting conn referred to by a socket generally results to use-after-free. When cleaning up SCO connections when the parent ACL is deleted too early, use hci_conn_failed to do the connection cleanup properly. We also need to clean up ISO connections in a similar situation when connecting has started but LE Create CIS is not yet sent, so do it too here.

Affected products

Linux kernel: from 6.3.8 before 6.4; from 6.4.1 before 6.4.16; from 6.5 before 6.5.3; 6.4, 6.4-rc4, 6.4-rc5, 6.4-rc6, 6.4-rc7 — fixed in 6.4, 6.4.16, 6.5.3

How to fix

Upgrade to a fixed version: Linux kernel 6.4, 6.4.16, 6.5.3. Check the vendor advisory for mitigations.

References

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