Vulnerability-Lookup

CVE-2026-64439 (GCVE-0-2026-64439)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:51 – Updated: 2026-07-25 08:51

Title

crypto: krb5 - filter out async aead implementations at alloc

Summary

In the Linux kernel, the following vulnerability has been resolved: crypto: krb5 - filter out async aead implementations at alloc krb5_aead_encrypt(), krb5_aead_decrypt() in rfc3961_simplified.c and rfc8009_encrypt(), rfc8009_decrypt() in rfc8009_aes2.c set a NULL completion callback and treat any negative return from crypto_aead_{encrypt,decrypt}() as terminal, falling through to kfree_sensitive(buffer). When the encrypt_name resolves to an async AEAD instance the request returns -EINPROGRESS, the buffer is freed while the backend's worker still holds a pointer, and the worker dereferences the freed slab on completion. KASAN report under UML+SLUB with a synthetic async aead backend bound to krb5->encrypt_name: BUG: KASAN: slab-use-after-free in t5_stub_complete+0x7d/0xc7 The helpers were written synchronously, so filter the async instances out at allocation time instead of plumbing crypto_wait_req() through every call site. Reachable via net/rxrpc/rxgk.c, fs/afs/cm_security.c and net/ceph/crypto.c on systems with an async AEAD provider bound to the krb5 enctype name.

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/ef6feb77e2d917614…
https://git.kernel.org/stable/c/2b7bd6dccff14b8b6…
https://git.kernel.org/stable/c/6c9dddeb582fde005…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 00244da40f7821b242c4612428d4192230dba27f , < ef6feb77e2d91761427c5b773edc9c97e1b706ad (git) Affected: 00244da40f7821b242c4612428d4192230dba27f , < 2b7bd6dccff14b8b632c5244f1fd506918077221 (git) Affected: 00244da40f7821b242c4612428d4192230dba27f , < 6c9dddeb582fde005360f4fe02c760d45ca05fb5 (git)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
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          "programFiles": [
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              "version": "0",
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: krb5 - filter out async aead implementations at alloc\n\nkrb5_aead_encrypt(), krb5_aead_decrypt() in rfc3961_simplified.c and\nrfc8009_encrypt(), rfc8009_decrypt() in rfc8009_aes2.c set a NULL\ncompletion callback and treat any negative return from\ncrypto_aead_{encrypt,decrypt}() as terminal, falling through to\nkfree_sensitive(buffer).  When the encrypt_name resolves to an\nasync AEAD instance the request returns -EINPROGRESS, the buffer\nis freed while the backend\u0027s worker still holds a pointer, and the\nworker dereferences the freed slab on completion.\n\nKASAN report under UML+SLUB with a synthetic async aead backend\nbound to krb5-\u003eencrypt_name:\n\n  BUG: KASAN: slab-use-after-free in t5_stub_complete+0x7d/0xc7\n\nThe helpers were written synchronously, so filter the async\ninstances out at allocation time instead of plumbing\ncrypto_wait_req() through every call site.\n\nReachable via net/rxrpc/rxgk.c, fs/afs/cm_security.c and\nnet/ceph/crypto.c on systems with an async AEAD provider bound to\nthe krb5 enctype name."
        }
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        {
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    "datePublished": "2026-07-25T08:51:12.422Z",
    "dateReserved": "2026-07-19T15:36:31.788Z",
    "dateUpdated": "2026-07-25T08:51:12.422Z",
    "state": "PUBLISHED"
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    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-07-25T15:59:19Z",
      "cve": "CVE-2026-64439",
      "id": "CVE-2026-64439",
      "initial_release_date": "2026-07-25T15:59:19Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64439",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64439.json",
      "version": "2"
    }
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}

GHSA-F86V-42XW-Q4VJ

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-25 12:31

Details

In the Linux kernel, the following vulnerability has been resolved:

crypto: krb5 - filter out async aead implementations at alloc

krb5_aead_encrypt(), krb5_aead_decrypt() in rfc3961_simplified.c and rfc8009_encrypt(), rfc8009_decrypt() in rfc8009_aes2.c set a NULL completion callback and treat any negative return from crypto_aead_{encrypt,decrypt}() as terminal, falling through to kfree_sensitive(buffer). When the encrypt_name resolves to an async AEAD instance the request returns -EINPROGRESS, the buffer is freed while the backend's worker still holds a pointer, and the worker dereferences the freed slab on completion.

KASAN report under UML+SLUB with a synthetic async aead backend bound to krb5->encrypt_name:

BUG: KASAN: slab-use-after-free in t5_stub_complete+0x7d/0xc7

The helpers were written synchronously, so filter the async instances out at allocation time instead of plumbing crypto_wait_req() through every call site.

Reachable via net/rxrpc/rxgk.c, fs/afs/cm_security.c and net/ceph/crypto.c on systems with an async AEAD provider bound to the krb5 enctype name.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-64439"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:28Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: krb5 - filter out async aead implementations at alloc\n\nkrb5_aead_encrypt(), krb5_aead_decrypt() in rfc3961_simplified.c and\nrfc8009_encrypt(), rfc8009_decrypt() in rfc8009_aes2.c set a NULL\ncompletion callback and treat any negative return from\ncrypto_aead_{encrypt,decrypt}() as terminal, falling through to\nkfree_sensitive(buffer).  When the encrypt_name resolves to an\nasync AEAD instance the request returns -EINPROGRESS, the buffer\nis freed while the backend\u0027s worker still holds a pointer, and the\nworker dereferences the freed slab on completion.\n\nKASAN report under UML+SLUB with a synthetic async aead backend\nbound to krb5-\u003eencrypt_name:\n\n  BUG: KASAN: slab-use-after-free in t5_stub_complete+0x7d/0xc7\n\nThe helpers were written synchronously, so filter the async\ninstances out at allocation time instead of plumbing\ncrypto_wait_req() through every call site.\n\nReachable via net/rxrpc/rxgk.c, fs/afs/cm_security.c and\nnet/ceph/crypto.c on systems with an async AEAD provider bound to\nthe krb5 enctype name.",
  "id": "GHSA-f86v-42xw-q4vj",
  "modified": "2026-07-25T12:31:35Z",
  "published": "2026-07-25T12:31:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64439"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2b7bd6dccff14b8b632c5244f1fd506918077221"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6c9dddeb582fde005360f4fe02c760d45ca05fb5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ef6feb77e2d91761427c5b773edc9c97e1b706ad"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-64439 (GCVE-0-2026-64439)

GHSA-F86V-42XW-Q4VJ

Tags

Sightings

Nomenclature