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af_unix: Update last skb marker in manage_oob().

Type: advisorySource: Official CVE List1 source record

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.

Announced Group revision 1
Original source ↗

CVE-2026-97985

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-97985

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
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Prerequisites
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Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "022d81a709cd553bbe2db8675f8e824f4aee6284",
        "lessThan": "bd91dc313afe21e9d6b31ca6a47606a33ca5e35c",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "22dd70eb2c3d754862964377a75abafd3167346b",
        "lessThan": "0630bfc773d85ac44da05b2c5a037dbbd39301ab",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "22dd70eb2c3d754862964377a75abafd3167346b",
        "lessThan": "f1816b3d7ce80dcf086bb68ff5ae6e09520ca1fa",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "22dd70eb2c3d754862964377a75abafd3167346b",
        "lessThan": "fc62a26493a98a0424d9dae2eb92a1daa1321f65",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "22dd70eb2c3d754862964377a75abafd3167346b",
        "lessThan": "94fd4debd2e3a69cf93e766c8b328a810c228119",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "ae3f9e1221b31b18dbd4c4b85d08574996bbd973",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "ba0db4638525b8b054b3d546b45f7e473f477027",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "16dc252e7007547a7b72a2c21022ef81fb45e6a3",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6.6.29",
        "lessThan": "6.6.160",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "5.15.157",
        "lessThan": "5.16",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "6.1.88",
        "lessThan": "6.2",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "6.8.8",
        "lessThan": "6.9",
        "versionType": "semver"
      }
    ],
    "programFiles": [
      "net/unix/af_unix.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.9"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "6.9",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.160",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.111",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.53",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.7",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/unix/af_unix.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-97985

Source reference: /cveMetadata/cveId

Publisher severity

No explicit severity was provided.

Event
#48822 · Revision 1
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Revision history

  1. CVE-2026-97985 · Revision 1Source updated