af_unix: Update last skb marker in manage_oob().
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 2 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: af_unix: Update last skb marker in manage_oob(). Fahad Alharbi reported that blocking recv(MSG_PEEK) could hog CPU due to OOB skb. In the following cases, manage_oob() skips OOB skb(s) and returns NULL for the last recv(MSG_PEEK): socketpair(AF_UNIX, SOCK_STREAM, 0, sk); 1) skb -> OOB skb -> NULL send(sk[0], "ab", 2, MSG_OOB); recv(sk[1], buf, 0, MSG_PEEK); 2) skb -> consumed OOB skb -> NULL send(sk[0], "ab", 2, MSG_OOB); recv(sk[1], buf, 1, MSG_OOB); recv(sk[1], buf, 0, MSG_PEEK); 3) consumed OOB skb -> OOB skb -> NULL send(sk[0], "a", 1, MSG_OOB); recv(sk[1], buf, 0, MSG_OOB); send(sk[0], "b", 1, MSG_OOB); recv(sk[1], buf, 1, MSG_PEEK); Then, @copied is 0 in unix_stream_read_generic() (zero-length buffer, or non-OOB skb is not yet consumed), and unix_stream_data_wait() is called. However, it returns immediately because @last is not updated in unix_stream_read_generic(), and the thread busy-waits for a new skb. Let's update @last in manage_oob(). For MSG_PEEK, @last is updated with the skipped OOB, and for the non-peek case, @last matches the returned value (when !copied) because OOB is unlinked. Note that manage_oob() is inlined and no stack canary is added.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.6.160, 5.16, 6.2, 6.9
- Fix · CNA Linux (Linux) Fixed in 6.6.160, 6.12.111, 6.18.53, 7.2.7, 7.3
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
Not affected: 5 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-97985
- 2026-10-03 Alias added: GHSA-cq66-2f6w-rhg5
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Fix available: Linux/[email protected], Linux/Linux@bd91dc313afe21e9d6b31ca6a47606a33ca5e35c · CNA
- 2026-10-21 1 new reference · CNA
- 2026-11-07 Affected versions changed · Red Hat
References
Other 5
- https://git.kernel.org/stable/c/bd91dc313afe21e9d6b31ca6a47606a33ca5e35c
- https://git.kernel.org/stable/c/0630bfc773d85ac44da05b2c5a037dbbd39301ab
- https://git.kernel.org/stable/c/f1816b3d7ce80dcf086bb68ff5ae6e09520ca1fa
- https://git.kernel.org/stable/c/fc62a26493a98a0424d9dae2eb92a1daa1321f65
- https://git.kernel.org/stable/c/94fd4debd2e3a69cf93e766c8b328a810c228119
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Sources
- CVE-2026-97985 · CVE Program
- CVE-2026-97985 · NVD
- FIRST EPSS
- GHSA-cq66-2f6w-rhg5 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-97985 · Red Hat security data · CC BY 4.0
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