Vulnerability-Lookup

FKIE_CVE-2025-39941

Vulnerability from fkie_nvd - Published: 2025-10-04 08:15 - Updated: 2026-01-23 20:37

Severity ?

4.7 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: zram: fix slot write race condition Parallel concurrent writes to the same zram index result in leaked zsmalloc handles. Schematically we can have something like this: CPU0 CPU1 zram_slot_lock() zs_free(handle) zram_slot_lock() zram_slot_lock() zs_free(handle) zram_slot_lock() compress compress handle = zs_malloc() handle = zs_malloc() zram_slot_lock zram_set_handle(handle) zram_slot_lock zram_slot_lock zram_set_handle(handle) zram_slot_lock Either CPU0 or CPU1 zsmalloc handle will leak because zs_free() is done too early. In fact, we need to reset zram entry right before we set its new handle, all under the same slot lock scope.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ce4be9e4307c5a60701ff6e0cafa74caffdc54ce	Patch
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ff750e9f2c4d63854c33967d1646b5e89a9a19a2	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	6.17
linux	linux_kernel	6.17
linux	linux_kernel	6.17
linux	linux_kernel	6.17
linux	linux_kernel	6.17
linux	linux_kernel	6.17

JSON

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{
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    {
      "nodes": [
        {
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              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "EE235AB0-05B1-418B-ADD0-620D5ABC03B9",
              "versionEndExcluding": "6.16.9",
              "versionStartIncluding": "6.14",
              "vulnerable": true
            },
            {
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    }
  ],
  "id": "CVE-2025-39941",
  "lastModified": "2026-01-23T20:37:16.010",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
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        "impactScore": 3.6,
        "source": "nvd@nist.gov",
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  "vulnStatus": "Analyzed",
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        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2025-39941 (GCVE-0-2025-39941)

Vulnerability from cvelistv5 – Published: 2025-10-04 07:31 – Updated: 2025-10-04 07:31

Title

zram: fix slot write race condition

Summary

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/ff750e9f2c4d63854…
	https://git.kernel.org/stable/c/ce4be9e4307c5a607…

Impacted products

Vendor

Product

Version

Linux

Affected: 71268035f5d734ad6373d953298bd5779985497a , < ff750e9f2c4d63854c33967d1646b5e89a9a19a2 (git)
Affected: 71268035f5d734ad6373d953298bd5779985497a , < ce4be9e4307c5a60701ff6e0cafa74caffdc54ce (git)

Linux

Affected: 6.14
Unaffected: 0 , < 6.14 (semver)
Unaffected: 6.16.9 , ≤ 6.16.* (semver)
Unaffected: 6.17 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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": [
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              "lessThan": "ff750e9f2c4d63854c33967d1646b5e89a9a19a2",
              "status": "affected",
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            }
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              "version": "0",
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              "versionType": "semver"
            },
            {
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              "version": "6.17",
              "versionType": "original_commit_for_fix"
            }
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          "lang": "en",
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}

Sightings

Author	Source	Type	Date

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.

Action not permitted

FKIE_CVE-2025-39941

CVE-2025-39941 (GCVE-0-2025-39941)

Tags

Sightings

Nomenclature