Loop with Unreachable Exit Condition ('Infinite Loop') Affecting kernel-rt-64k package, versions *


Severity

Recommended
low

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.17% (6th percentile)

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  • Snyk IDSNYK-RHEL10-KERNELRT64K-20345832
  • published1 Oct 2026
  • disclosed25 Sept 2026

Introduced: 25 Sep 2026

NewCVE-2026-97985  (opens in a new tab)
CWE-835  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 kernel-rt-64k.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-64k package and not the kernel-rt-64k package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1