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CVE-2026-64368 (GCVE-0-2026-64368)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:50 – Updated: 2026-08-17 04:54
VLAI
Title
mm/slab: do not limit zeroing to orig_size when only red zoning is enabled
Summary
In the Linux kernel, the following vulnerability has been resolved: mm/slab: do not limit zeroing to orig_size when only red zoning is enabled When init (zeroing) on allocation is requested, for kmalloc() we generally have to zero the full object size even if a smaller size is requested, in order to provide krealloc()'s __GFP_ZERO guarantees. But if we track the requested size, krealloc() uses that information to do the right thing, so we can zero only the requested size. With red zoning also enabled, any extra size became part of the red zone, so it must not be zeroed and thus we must zero only the requested size. However the current check is imprecise, and will trigger also when only SLAB_RED_ZONE is enabled without SLAB_STORE_USER (which enables tracking the requested size). This means enabling red zoning alone can compromise krealloc()'s __GFP_ZERO contract. Fix this by using slub_debug_orig_size() instead, which is the exact check for whether the requested size is tracked. We don't need to care if red zoning is also enabled or not. Also update and expand the comment accordingly.
Severity
8.1 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 9ce67395f5a0cdec6ce152d26bfda13b98b25c01 , < 6256899c3a34674bba6076884aedbba49fc695e4 (git)
Affected: 9ce67395f5a0cdec6ce152d26bfda13b98b25c01 , < 7e706d50fa119eead6376bf0ef973e8d73a96030 (git)
Affected: 9ce67395f5a0cdec6ce152d26bfda13b98b25c01 , < 2382971aaaef5bf85a651234c64906f59580b8be (git)
Affected: 9ce67395f5a0cdec6ce152d26bfda13b98b25c01 , < 0d18ccef142f04433dfb2a0c120cf223d2b8a42c (git)
Affected: 9ce67395f5a0cdec6ce152d26bfda13b98b25c01 , < 648927ceb84021a25a0fbd5673740956f318d534 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.2
Unaffected: 0 , < 6.2 (semver)
Unaffected: 6.6.145 , ≤ 6.6.* (semver)
Unaffected: 6.12.96 , ≤ 6.12.* (semver)
Unaffected: 6.18.39 , ≤ 6.18.* (semver)
Unaffected: 7.1.4 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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    "redhat_vex": {
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      "title": "kernel: mm/slab: do not limit zeroing to orig_size when only red zoning is enabled",
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      "cve": "CVE-2026-64368",
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      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64368",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64368.json",
      "version": "6"
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  }
}



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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

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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.