UBUNTU-CVE-2026-93824: High severity ubuntu/linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: tls: reject the combination of TLS and sockmap TLS and sockmap (BPF psock) integration hides a lot of latent bugs. Bugs which may be more or less relevant for real users but they are definitely exploitable. We could not find anyone actively using this integration so let's reject this config. Adding a TLS socket to a sockmap was already rejected by skpsockinit() through the inetcskhasulp() check. We need to reject the attempts to configure the TLS keys (rather than adding the ULP itself) because checking prior to the ULP installation is tricky without risking a race with sockmap getting added in parallel (sockmap does not hold the socket lock). This patch is a minimal rejection of the feature. Subsequent patch in the series will do a light dead code removal. Full cleanup would require a major rewrite of the Tx path, we don't need skmsg any more.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Configuration
Do not configure TLS keys or add TLS sockets to a sockmap; reject the TLS-and-sockmap configuration.
Linux kernel TLS and sockmap (BPF psock) integration TLS and sockmap combination = disabled
Event History
Frequently Asked Questions
Who is realistically exposed to this issue?
Exposure is limited to systems using both kernel TLS and sockmap (BPF psock) integration. The description states that no active users of this integration were found, but the latent bugs are considered exploitable.
What access does an attacker need?
The supplied CVSS vector indicates local access, low attack complexity, no user interaction, and high privileges required. The impact is high for confidentiality, integrity, and availability within the vulnerable system.
Which Ubuntu kernel packages are listed as affected?
The listed software includes ubuntu/linux, ubuntu/linux-fips, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-aws-fips, ubuntu/linux-azure-fips, and ubuntu/linux-gcp-fips.
What mitigation is described if an update cannot be applied immediately?
Avoid configuring TLS keys on sockets that participate in sockmap integration, and avoid using the TLS-plus-sockmap combination. The resolution rejects attempts to configure TLS keys in this scenario.