CVE-2026-98253

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/ucma: Serialize join and leave on copy_to_user failure rdma_join_multicast() queues RoCE work that later reads the ucma_multicast through event->param.ud.private_data, then list_add()s the CMA multicast at the head of id_priv->mc_list. rdma_leave_multicast() matches only by sockaddr and destroys the first hit. ucma_process_join() used to drop ctx->mutex after a successful join and retake it only if copy_to_user() failed. Two concurrent JOIN_MCAST calls with the same address can therefore insert a second CMA entry before the first thread's leave. leave then cancels the newer work and the older worker still dereferences the ucma_multicast that the first thread frees. Keep ctx->mutex held from rdma_join_multicast() through copy_to_user() and, on -EFAULT, through rdma_leave_multicast() so leave cannot miss this join. Do not leave if join itself failed: that path never published this address on mc_list, and a leave-by-addr would destroy an earlier successful join.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-06 09:18:13.887000

Last modified

2026-10-19 10:18:26.240000

View original CVE JSON

{
  "id": "CVE-2026-98253",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-06T09:18:13.887",
  "lastModified": "2026-10-19T10:18:26.240",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/ucma: Serialize join and leave on copy_to_user failure\n\nrdma_join_multicast() queues RoCE work that later reads the ucma_multicast\nthrough event->param.ud.private_data, then list_add()s the CMA multicast\nat the head of id_priv->mc_list. rdma_leave_multicast() matches only by\nsockaddr and destroys the first hit.\n\nucma_process_join() used to drop ctx->mutex after a successful join and\nretake it only if copy_to_user() failed. Two concurrent JOIN_MCAST calls\nwith the same address can therefore insert a second CMA entry before the\nfirst thread's leave. leave then cancels the newer work and the older\nworker still dereferences the ucma_multicast that the first thread frees.\n\nKeep ctx->mutex held from rdma_join_multicast() through copy_to_user() and,\non -EFAULT, through rdma_leave_multicast() so leave cannot miss this join.\nDo not leave if join itself failed: that path never published this address\non mc_list, and a leave-by-addr would destroy an earlier successful join."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/infiniband/core/ucma.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "60d613b39e8d0c9f3b526e9c96445422b4562d76",
              "lessThan": "29b9ed83d8bfab5c6e11fcbf1aa836aa4ae26cb9",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "fe454dc31e84f8c14cb8942fcb61666c9f40745b",
              "lessThan": "52172e11bd074ccaded21740ffeb67123f01dd00",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "fe454dc31e84f8c14cb8942fcb61666c9f40745b",
              "lessThan": "01e29d0d78a8f66f221625720a04939eef5ec1f6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "fe454dc31e84f8c14cb8942fcb61666c9f40745b",
              "lessThan": "ae805d204cf1f15b87d1bf3529b4c649f3519420",
              "versionType": "git",
              "status": "affected"
            },
            {
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              "lessThan": "43c4e24bd10370fc976f6220518049ce71419399",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "fe454dc31e84f8c14cb8942fcb61666c9f40745b",
              "lessThan": "01cbdb724c584d7772fd25af2e4dfdf8527ce0d5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "fe454dc31e84f8c14cb8942fcb61666c9f40745b",
              "lessThan": "83610ee5e498fa5bfcb80031d2b959baea276bf6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "fe454dc31e84f8c14cb8942fcb61666c9f40745b",
              "lessThan": "662ade4de9ff5eceb0820a9f8e9fac70ba6a815b",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a3262b3884dd67b4c5632ce7cdf9cff9d1a575d4",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5.10.20",
              "lessThan": "5.10.271",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "5.11.3",
              "lessThan": "5.12",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/infiniband/core/ucma.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.12",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.12",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.271",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.222",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.189",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.112",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.54",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.8",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/01cbdb724c584d7772fd25af2e4dfdf8527ce0d5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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}