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kcm: use WRITE_ONCE() when changing lower socket callbacks

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: kcm: use WRITE_ONCE() when changing lower socket callbacks kcm_attach() replaces a live lower TCP socket's sk_data_ready and sk_write_space callbacks with KCM handlers, and kcm_unattach() restores them later. Those callback-pointer updates are still plain stores even though the same fields can be read and invoked concurrently on other CPUs. If another CPU observes an older callback snapshot after the live field has already been restored, callback execution can run with a mismatched target and sk_user_data state, leading to stale or misdirected wakeups. Use WRITE_ONCE() for the callback replacement and restore operations so these shared callback fields follow the same visibility contract already established by the earlier 4022 fixes.

Announced Source revision 1
Original source ↗

CVE-2026-74262

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-2026-74262

Linux

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

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

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": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
        "lessThan": "0cb3e2f40679032c1aa2186280a86e5ead0161ee",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
        "lessThan": "fa26e4606aed0f7fe793c325506adeda1d847a43",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
        "lessThan": "b4ccd6eef671d7c44a30123cd29f3acf3de8468e",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
        "lessThan": "b8c90823cdfb5f3d22f261aeb3e9066612853c36",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
        "lessThan": "11faefd11ce2448bac7279ab302dd1954a6547fe",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
        "lessThan": "f01fb6138f8eb606b56ce9158e2d8b72352c53f4",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
        "lessThan": "9684fff87124b201e11dea01ded9173025359a0f",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3",
        "lessThan": "47186409c092cd7dd70350999186c700233e854d",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/kcm/kcmsock.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "4.6"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "4.6",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.261",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.212",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.178",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.145",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.97",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.40",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.1.5",
        "versionType": "semver",
        "lessThanOrEqual": "7.1.*"
      },
      {
        "status": "unaffected",
        "version": "7.2",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/kcm/kcmsock.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-74262

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#33072 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement