CVE-2026-68393: Bluetooth: hci_sync: extend conn_hash lookup critical sections
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hcisync: extend connhash lookup critical sections
Using RCU-protected pointers outside the critical sections without refcount is incorrect and may result to UAF.
Extend critical section to cover both hciconnhash lookup and use of the returned conn.
Add surrounding rcureadlock() also when return value is not used, in preparation for RCU lockdep requirement to hcilookupleconnect().
This avoids concurrent deletion of the conn before we are done dereferencing it.
Also, make sure to hold hdev->lock when accessing hdev->acceptlist.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
Upgrade
ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38~24.04.4 - Upgrade
Upgrade
ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-38.38 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1008.9 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Compensating control
Wrap hci_conn_hash lookup and use of the returned connection in an rcu_read_lock() critical section, including when the return value of hci_lookup_le_connect() is not used, to prevent concurrent deletion before dereferencing.
- Compensating control
Hold hdev->lock whenever accessing hdev->accept_list.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-68393?
CVE-2026-68393 has a risk rating of 47, indicating a critical vulnerability.
How do I fix CVE-2026-68393?
To address CVE-2026-68393, ensure that you are using a patched version of the Linux kernel that resolves this Bluetooth connection issue.
What systems are affected by CVE-2026-68393?
CVE-2026-68393 affects the Linux kernel, specifically Bluetooth functionality.
What are the potential consequences of CVE-2026-68393?
Exploiting CVE-2026-68393 may lead to use-after-free errors which could compromise system stability and security.
When was CVE-2026-68393 published?
CVE-2026-68393 was published on August 10, 2026.