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zram: fix out-of-bounds access in writeback_store()

Type: advisorySource: Official CVE List1 source record

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.

Announced Source revision 1
Original source ↗

CVE-2026-89718

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-2026-89718

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": "a939888ec38bf1f33e4a903056677e92a4844244",
        "lessThan": "c2745e657f0974871fbc60d46d48c2b04e581330",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a939888ec38bf1f33e4a903056677e92a4844244",
        "lessThan": "4d82d60178b02797dbe529e01ac211b26670c49f",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a939888ec38bf1f33e4a903056677e92a4844244",
        "lessThan": "ef073edd7cfd31aeb90eeab23273102c601f4d8e",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a939888ec38bf1f33e4a903056677e92a4844244",
        "lessThan": "07a82a66f8c1894d92e51d97542c32ebf2c51b09",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "a939888ec38bf1f33e4a903056677e92a4844244",
        "lessThan": "894913e2d35c46ff19a77530907771ae57862b96",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/block/zram/zram_drv.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "5.0"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "5.0",
        "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": "6.18.57",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.4",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/block/zram/zram_drv.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-89718

Source reference: /cveMetadata/cveId

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No explicit severity was provided.

Event
#46714 · Revision 1
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