CVE-2026-68120: rtase: Workaround for TX hang caused by hardware packet parsing
In the Linux kernel, the following vulnerability has been resolved:
rtase: Workaround for TX hang caused by hardware packet parsing
The hardware performs packet parsing before packet transmission. Parsing incomplete IPv4, IPv6, TCP, or UDP headers may trigger a TX hang because the hardware parser expects additional protocol header data that is not present in the packet.
The hardware performs additional PTP parsing on UDP packets identified by destination ports 319/320 at the expected UDP destination port offset.
If such a packet has transport data smaller than RTASEMINPADLEN, the hardware parser expects additional packet data and may trigger a TX hang.
To avoid these hardware issues, the driver applies the following workarounds.
Drop malformed packets that may trigger this hardware issue before transmission.
For IPv4 non-initial fragments, the hardware does not check the fragment offset before parsing the expected transport header location. As a result, these packets are still subject to transport header parsing even though they do not contain a transport header. If the transport data is shorter than the minimum transport header required by the hardware parser, pad the transport data to the minimum transport header length required by the hardware parser. Packets that also match the hardware PTP parsing conditions continue to follow the corresponding workaround.
For IPv6 fragmented packets, neither of the above hardware issues occurs because the hardware only continues packet parsing when the IPv6 Base Header Next Header field directly indicates UDP. Packets carrying a Fragment Header do not continue through the subsequent packet parsing stages.
For packets identified for hardware PTP parsing, pad the transport data so it reaches RTASEMINPADLEN before transmission.
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
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ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17~24.04.1 - Upgrade
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ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
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ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38~24.04.4 - Upgrade
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ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1024.25~24.04.1 - Upgrade
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ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-38.38 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1008.9 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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ubuntu/linux-nvidia-bosto a version that resolves this vulnerability.Fixed in 7.0.0-2022.23 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
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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
In the rtase driver, drop malformed packets that may trigger the hardware packet-parsing TX hang before transmission, including packets with incomplete IPv4, IPv6, TCP, or UDP headers and IPv4 non-initial fragments whose fragment offset is not checked before transport-header parsing.
- Compensating control
In the rtase driver, pad transport data to the minimum transport-header length required by the hardware parser when the transport data is shorter than that length.
- Compensating control
For packets identified for hardware PTP parsing—UDP destination ports 319/320—pad the transport data so it reaches RTASE_MIN_PAD_LEN before transmission.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-68120?
CVE-2026-68120 has a risk rating of 21.
How do I fix CVE-2026-68120?
To fix CVE-2026-68120, you should update to the latest version of the Linux kernel that includes the fix.
What symptoms indicate CVE-2026-68120 is affecting my system?
Symptoms of CVE-2026-68120 include a transmission hang during hardware packet parsing.
Which software is impacted by CVE-2026-68120?
CVE-2026-68120 impacts the Linux kernel.
When was CVE-2026-68120 published?
CVE-2026-68120 was published on August 10, 2026.