GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-72292 (GCVE-0-2026-72292)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:55 – Updated: 2026-08-17 05:11
VLAI
Title
KVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory kvm_s390_get_cmma_bits() allocates its output buffer with vmalloc(), which does not zero the returned pages: values = vmalloc(args->count); In the non-peek (migration) path, dat_get_cmma() reports a byte count spanning from the first to the last dirty page, but __dat_get_cmma_pte() writes values[gfn - start] only for pages whose CMMA dirty bit is set. The walk uses DAT_WALK_IGN_HOLES, so clean and unmapped pages that lie between two dirty pages within the reported span are visited but never store their byte. Those gaps (up to KVM_S390_MAX_BIT_DISTANCE pages each) stay uninitialized yet fall inside [0, count) and are copied out by copy_to_user(), disclosing stale kernel memory to user space. Before the switch to the new gmap implementation the buffer was fully populated for every gfn in the span, so no uninitialized bytes were exposed; the dirty-only walk introduced the leak. Use vzalloc() so the gaps read back as zero.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: e38c884df92119d96f652d51f82661dd2fc0b885 , < a4a19941ccb2164edc3491faa5ac5df82e94b363 (git)
Affected: e38c884df92119d96f652d51f82661dd2fc0b885 , < c7dda3d0f869dc97223448a06c9a2e5235928e48 (git)
guessed Create a notification for this product.
Linux Linux Affected: 7.0
Unaffected: 0 , < 7.0 (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/s390/kvm/kvm-s390.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a4a19941ccb2164edc3491faa5ac5df82e94b363",
              "status": "affected",
              "version": "e38c884df92119d96f652d51f82661dd2fc0b885",
              "versionType": "git"
            },
            {
              "lessThan": "c7dda3d0f869dc97223448a06c9a2e5235928e48",
              "status": "affected",
              "version": "e38c884df92119d96f652d51f82661dd2fc0b885",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/s390/kvm/kvm-s390.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.0"
            },
            {
              "lessThan": "7.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory\n\nkvm_s390_get_cmma_bits() allocates its output buffer with vmalloc(),\nwhich does not zero the returned pages:\n\n\tvalues = vmalloc(args-\u003ecount);\n\nIn the non-peek (migration) path, dat_get_cmma() reports a byte count\nspanning from the first to the last dirty page, but __dat_get_cmma_pte()\nwrites values[gfn - start] only for pages whose CMMA dirty bit is set.\nThe walk uses DAT_WALK_IGN_HOLES, so clean and unmapped pages that lie\nbetween two dirty pages within the reported span are visited but never\nstore their byte.  Those gaps (up to KVM_S390_MAX_BIT_DISTANCE pages\neach) stay uninitialized yet fall inside [0, count) and are copied out\nby copy_to_user(), disclosing stale kernel memory to user space.\n\nBefore the switch to the new gmap implementation the buffer was fully\npopulated for every gfn in the span, so no uninitialized bytes were\nexposed; the dirty-only walk introduced the leak.\n\nUse vzalloc() so the gaps read back as zero."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:11:54.937Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/a4a19941ccb2164edc3491faa5ac5df82e94b363"
        },
        {
          "url": "https://git.kernel.org/stable/c/c7dda3d0f869dc97223448a06c9a2e5235928e48"
        }
      ],
      "title": "KVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72292",
    "datePublished": "2026-08-15T05:55:13.248Z",
    "dateReserved": "2026-08-09T03:40:39.917Z",
    "dateUpdated": "2026-08-17T05:11:54.937Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-72292",
      "date": "2026-09-05",
      "epss": "0.00198",
      "percentile": "0.09606"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-72292\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-15T06:22:01.377\",\"lastModified\":\"2026-08-17T06:18:32.017\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nKVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory\\n\\nkvm_s390_get_cmma_bits() allocates its output buffer with vmalloc(),\\nwhich does not zero the returned pages:\\n\\n\\tvalues = vmalloc(args-\u003ecount);\\n\\nIn the non-peek (migration) path, dat_get_cmma() reports a byte count\\nspanning from the first to the last dirty page, but __dat_get_cmma_pte()\\nwrites values[gfn - start] only for pages whose CMMA dirty bit is set.\\nThe walk uses DAT_WALK_IGN_HOLES, so clean and unmapped pages that lie\\nbetween two dirty pages within the reported span are visited but never\\nstore their byte.  Those gaps (up to KVM_S390_MAX_BIT_DISTANCE pages\\neach) stay uninitialized yet fall inside [0, count) and are copied out\\nby copy_to_user(), disclosing stale kernel memory to user space.\\n\\nBefore the switch to the new gmap implementation the buffer was fully\\npopulated for every gfn in the span, so no uninitialized bytes were\\nexposed; the dirty-only walk introduced the leak.\\n\\nUse vzalloc() so the gaps read back as zero.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"arch/s390/kvm/kvm-s390.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"e38c884df92119d96f652d51f82661dd2fc0b885\",\"lessThan\":\"a4a19941ccb2164edc3491faa5ac5df82e94b363\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"e38c884df92119d96f652d51f82661dd2fc0b885\",\"lessThan\":\"c7dda3d0f869dc97223448a06c9a2e5235928e48\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"arch/s390/kvm/kvm-s390.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"7.0\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"7.0\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/a4a19941ccb2164edc3491faa5ac5df82e94b363\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c7dda3d0f869dc97223448a06c9a2e5235928e48\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-18T11:22:41+00:00",
      "cve": "CVE-2026-72292",
      "id": "CVE-2026-72292",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_affected": "14",
      "product_status:known_not_affected": "260",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: KVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72292.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.