Bug 2552217 (CVE-2026-98394)

Summary: CVE-2026-98394 kernel: af_unix: Return immediately when manage_oob() returns NULL for 0-length buffer
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's UNIX domain socket (af_unix) implementation. When a blocking receive operation is performed using a zero-length buffer and the peek flag on a socket where the last queued message contains out-of-band (OOB) data, the kernel fails to return properly. A local attacker could exploit this vulnerability to trigger an infinite busy-wait loop, consuming excessive processor resources and leading to a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-10-14 13:47:25 UTC 
In the Linux kernel, the following vulnerability has been resolved:

af_unix: Return immediately when manage_oob() returns NULL for 0-length buffer.

Fahad Alharbi reported that recv(0, MSG_PEEK) triggers busy-wait
in unix_stream_read_generic() if recv() is blocking and the last
skb in the queue is MSG_OOB skb.

In such a situation, TCP returns 0 immediately regardless of
blocking or non-blocking.

Let's follow the behaviour.