CVE-2026-89718 (GCVE-0-2026-89718)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:46 – Updated: 2026-10-30 12:32
VLAI
Title
zram: fix out-of-bounds access in writeback_store()
Summary
In the Linux kernel, the following vulnerability has been resolved: zram: fix out-of-bounds access in writeback_store() Patch series "zram: fix stale scan bounds after reinitialization". Both writeback_store() and read_block_state() derive their table scan bounds from zram->disksize before acquiring dev_lock. If the device is reset and reinitialized with a smaller disksize between that read and lock acquisition, the bound can describe the old table while the scan operates on the new one. This can lead to out-of-bounds slot accesses. Move both bound calculations under dev_lock so each bound remains consistent with the table throughout its scan. Keep the fixes separate because the affected interfaces originate from different commits and can be backported independently. This patch (of 2): writeback_store() calculates the table scan bounds before taking dev_lock. A reset followed by reconfiguration with a smaller disksize can therefore replace zram->table while writeback_store() is waiting for the lock. Once it acquires the lock, it sees an initialized device but scans the new table using the old upper bound, resulting in an out-of-bounds access. Calculate the number of pages while holding dev_lock so the scan bound matches the table protected by the lock.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6971 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: a939888ec38bf1f33e4a903056677e92a4844244 , < f1c5611f699a3aa2a85ebd5fec03dc9bc501e6d0 (git)
Affected: a939888ec38bf1f33e4a903056677e92a4844244 , < c2745e657f0974871fbc60d46d48c2b04e581330 (git)
Affected: a939888ec38bf1f33e4a903056677e92a4844244 , < 4d82d60178b02797dbe529e01ac211b26670c49f (git)
Affected: a939888ec38bf1f33e4a903056677e92a4844244 , < ef073edd7cfd31aeb90eeab23273102c601f4d8e (git)
Affected: a939888ec38bf1f33e4a903056677e92a4844244 , < 07a82a66f8c1894d92e51d97542c32ebf2c51b09 (git)
Affected: a939888ec38bf1f33e4a903056677e92a4844244 , < 894913e2d35c46ff19a77530907771ae57862b96 (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.0
Unaffected: 0 , < 5.0 (semver)
Unaffected: 6.1.191 , ≤ 6.1.* (semver)
Unaffected: 6.6.160 , ≤ 6.6.* (semver)
Unaffected: 6.12.111 , ≤ 6.12.* (semver)
Unaffected: 6.18.57 , ≤ 6.18.* (semver)
Unaffected: 7.2.4 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (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": [
            "drivers/block/zram/zram_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f1c5611f699a3aa2a85ebd5fec03dc9bc501e6d0",
              "status": "affected",
              "version": "a939888ec38bf1f33e4a903056677e92a4844244",
              "versionType": "git"
            },
            {
              "lessThan": "c2745e657f0974871fbc60d46d48c2b04e581330",
              "status": "affected",
              "version": "a939888ec38bf1f33e4a903056677e92a4844244",
              "versionType": "git"
            },
            {
              "lessThan": "4d82d60178b02797dbe529e01ac211b26670c49f",
              "status": "affected",
              "version": "a939888ec38bf1f33e4a903056677e92a4844244",
              "versionType": "git"
            },
            {
              "lessThan": "ef073edd7cfd31aeb90eeab23273102c601f4d8e",
              "status": "affected",
              "version": "a939888ec38bf1f33e4a903056677e92a4844244",
              "versionType": "git"
            },
            {
              "lessThan": "07a82a66f8c1894d92e51d97542c32ebf2c51b09",
              "status": "affected",
              "version": "a939888ec38bf1f33e4a903056677e92a4844244",
              "versionType": "git"
            },
            {
              "lessThan": "894913e2d35c46ff19a77530907771ae57862b96",
              "status": "affected",
              "version": "a939888ec38bf1f33e4a903056677e92a4844244",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/zram/zram_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.0"
            },
            {
              "lessThan": "5.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.191",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.57",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.191",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.160",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.111",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.57",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nzram: fix out-of-bounds access in writeback_store()\n\nPatch series \"zram: fix stale scan bounds after reinitialization\".\n\nBoth writeback_store() and read_block_state() derive their table scan\nbounds from zram-\u003edisksize before acquiring dev_lock.  If the device is\nreset and reinitialized with a smaller disksize between that read and lock\nacquisition, the bound can describe the old table while the scan operates\non the new one.  This can lead to out-of-bounds slot accesses.\n\nMove both bound calculations under dev_lock so each bound remains\nconsistent with the table throughout its scan.  Keep the fixes separate\nbecause the affected interfaces originate from different commits and can\nbe backported independently.\n\n\nThis patch (of 2):\n\nwriteback_store() calculates the table scan bounds before taking dev_lock.\nA reset followed by reconfiguration with a smaller disksize can therefore\nreplace zram-\u003etable while writeback_store() is waiting for the lock.  Once\nit acquires the lock, it sees an initialized device but scans the new\ntable using the old upper bound, resulting in an out-of-bounds access.\n\nCalculate the number of pages while holding dev_lock so the scan bound\nmatches the table protected by the lock."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-30T12:32:49.752Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f1c5611f699a3aa2a85ebd5fec03dc9bc501e6d0"
        },
        {
          "url": "https://git.kernel.org/stable/c/c2745e657f0974871fbc60d46d48c2b04e581330"
        },
        {
          "url": "https://git.kernel.org/stable/c/4d82d60178b02797dbe529e01ac211b26670c49f"
        },
        {
          "url": "https://git.kernel.org/stable/c/ef073edd7cfd31aeb90eeab23273102c601f4d8e"
        },
        {
          "url": "https://git.kernel.org/stable/c/07a82a66f8c1894d92e51d97542c32ebf2c51b09"
        },
        {
          "url": "https://git.kernel.org/stable/c/894913e2d35c46ff19a77530907771ae57862b96"
        }
      ],
      "title": "zram: fix out-of-bounds access in writeback_store()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89718",
    "datePublished": "2026-09-11T19:46:31.443Z",
    "dateReserved": "2026-09-11T19:38:34.752Z",
    "dateUpdated": "2026-10-30T12:32:49.752Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-89718",
      "date": "2026-11-01",
      "epss": "0.00173",
      "percentile": "0.06739"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "drivers/block/zram/zram_drv.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "f1c5611f699a3aa2a85ebd5fec03dc9bc501e6d0",
                    "status": "affected",
                    "version": "a939888ec38bf1f33e4a903056677e92a4844244",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "c2745e657f0974871fbc60d46d48c2b04e581330",
                    "status": "affected",
                    "version": "a939888ec38bf1f33e4a903056677e92a4844244",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "4d82d60178b02797dbe529e01ac211b26670c49f",
                    "status": "affected",
                    "version": "a939888ec38bf1f33e4a903056677e92a4844244",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "ef073edd7cfd31aeb90eeab23273102c601f4d8e",
                    "status": "affected",
                    "version": "a939888ec38bf1f33e4a903056677e92a4844244",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "07a82a66f8c1894d92e51d97542c32ebf2c51b09",
                    "status": "affected",
                    "version": "a939888ec38bf1f33e4a903056677e92a4844244",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "894913e2d35c46ff19a77530907771ae57862b96",
                    "status": "affected",
                    "version": "a939888ec38bf1f33e4a903056677e92a4844244",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "drivers/block/zram/zram_drv.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "5.0"
                  },
                  {
                    "lessThan": "5.0",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.1.*",
                    "status": "unaffected",
                    "version": "6.1.191",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.6.*",
                    "status": "unaffected",
                    "version": "6.6.160",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.12.*",
                    "status": "unaffected",
                    "version": "6.12.111",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.18.*",
                    "status": "unaffected",
                    "version": "6.18.57",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "7.2.*",
                    "status": "unaffected",
                    "version": "7.2.4",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.3",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nzram: fix out-of-bounds access in writeback_store()\n\nPatch series \"zram: fix stale scan bounds after reinitialization\".\n\nBoth writeback_store() and read_block_state() derive their table scan\nbounds from zram-\u003edisksize before acquiring dev_lock.  If the device is\nreset and reinitialized with a smaller disksize between that read and lock\nacquisition, the bound can describe the old table while the scan operates\non the new one.  This can lead to out-of-bounds slot accesses.\n\nMove both bound calculations under dev_lock so each bound remains\nconsistent with the table throughout its scan.  Keep the fixes separate\nbecause the affected interfaces originate from different commits and can\nbe backported independently.\n\n\nThis patch (of 2):\n\nwriteback_store() calculates the table scan bounds before taking dev_lock.\nA reset followed by reconfiguration with a smaller disksize can therefore\nreplace zram-\u003etable while writeback_store() is waiting for the lock.  Once\nit acquires the lock, it sees an initialized device but scans the new\ntable using the old upper bound, resulting in an out-of-bounds access.\n\nCalculate the number of pages while holding dev_lock so the scan bound\nmatches the table protected by the lock."
          }
        ],
        "id": "CVE-2026-89718",
        "lastModified": "2026-10-30T13:20:27.450",
        "metrics": {},
        "published": "2026-09-11T20:19:59.377",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/07a82a66f8c1894d92e51d97542c32ebf2c51b09"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/4d82d60178b02797dbe529e01ac211b26670c49f"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/894913e2d35c46ff19a77530907771ae57862b96"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/c2745e657f0974871fbc60d46d48c2b04e581330"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/ef073edd7cfd31aeb90eeab23273102c601f4d8e"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/f1c5611f699a3aa2a85ebd5fec03dc9bc501e6d0"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-10-17T21:35:51+00:00",
      "cve": "CVE-2026-89718",
      "id": "CVE-2026-89718",
      "initial_release_date": "2026-09-11T00:00:00+00:00",
      "product_status:known_affected": "186",
      "product_status:known_not_affected": "91",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: zram: fix out-of-bounds access in writeback_store()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89718.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-10-20T01:03:08Z",
      "cve": "CVE-2026-89718",
      "id": "CVE-2026-89718",
      "initial_release_date": "2026-09-17T16:41:03Z",
      "product_status:known_affected": "261",
      "product_status:known_not_affected": "93",
      "product_status:recommended": "4",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-89718",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/2026/cve-2026-89718.json",
      "version": "5"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON
How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.