CVE-2026-43021: Bluetooth: hci_sync: fix leaks when hci_cmd_sync_queue_once fails

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-01 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix leaks when hci_cmd_sync_queue_once fails When hci_cmd_sync_queue_once() returns with error, the destroy callback will not be called. Fix leaking references / memory on these failures.

Affected products

Linux kernel: from 6.19 before 6.19.12; 7.0-rc1, 7.0-rc2, 7.0-rc3, 7.0-rc4, 7.0-rc5, 7.0-rc6 — fixed in 6.19.12

How to fix

Upgrade to a fixed version: Linux kernel 6.19.12. Check the vendor advisory for mitigations.

References

https://git.kernel.org/stable/c/7fd74178d4b16dcf47179da634ea9d7c02e3608b
https://git.kernel.org/stable/c/aca377208e7f7322bf4e107cdec6e7d7e8aa7a88

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