CVE-2026-97985: af_unix: Update last skb marker in manage_oob().
afunix: Update last skb marker in manageoob().
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.159.1-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.113-1~deb12u1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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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
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1
Event History
Frequently Asked Questions
What conditions are needed to trigger the CPU hog?
The issue requires an AF_UNIX SOCK_STREAM socket handling out-of-band data and a blocking recv(MSG_PEEK) call after OOB skb entries have been skipped or consumed. The described cases include a zero-length MSG_PEEK receive and sequences involving MSG_OOB receives.
What is the observable impact?
The affected thread can busy-wait for a new skb and hog CPU. This occurs because the data-wait path returns immediately while no data has been copied.
How can I tell whether a system is encountering this issue?
Look for CPU consumption by a thread blocked in AF_UNIX stream receive handling, particularly where recv(MSG_PEEK) follows MSG_OOB activity. The reproductions use socketpair(AF_UNIX, SOCK_STREAM, 0, sk) and the specific OOB/peek receive sequences described in the advisory.