CVE-2026-97985

/// Technical description

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_r

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References