crypto: krb5enc - fix async decrypt skipping hash verification

{
  "id": "d07f16023193a57bb40df163e2459eefee7170e73a834687b77edc3bc19d22ec",
  "url": "https://osv.dev/vulnerability/CVE-2026-31719",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "crypto: krb5enc - fix async decrypt skipping hash verification",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: crypto: krb5enc - fix async decrypt skipping hash verification krb5enc_dispatch_decrypt() sets req->base.complete as the skcipher callback, which is the caller's own completion handler. When the skcipher completes asynchronously, this signals \"done\" to the caller without executing krb5enc_dispatch_decrypt_hash(), completely bypassing the integrity verification (hash check). Compare with the encrypt path which correctly uses krb5enc_encrypt_done as an intermediate callback to chain into the hash computation on async completion. Fix by adding krb5enc_decrypt_done as an intermediate callback that chains into krb5enc_dispatch_decrypt_hash() upon async skcipher completion, matching the encrypt path's callback pattern. Also fix EBUSY/EINPROGRESS handling throughout: remove krb5enc_request_complete() which incorrectly swallowed EINPROGRESS notifications that must be passed up to callers waiting on backlogged requests, and add missing EBUSY checks in krb5enc_encrypt_ahash_done for the dispatch_encrypt return value. Unset MAY_BACKLOG on the async completion path so the user won't see back-to-back EINPROGRESS notifications.",
    "evidence": "osv:CVE-2026-31719",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.25",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.2",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-31719",
      "aliases": [
        "CVE-2026-31719"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "d1775a177f7f38156d541c8a3e3c91eaa6e69699"
                },
                {
                  "fixed": "07cbb1bd424370671814a862913c99a6e1441588"
                },
                {
                  "fixed": "e51f42114abbdf47f29dda43e7826be28907fcd2"
                },
                {
                  "fixed": "3bfbf5f0a99c991769ec562721285df7ab69240b"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31719.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.15.0"
                },
                {
                  "fixed": "6.18.25"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.2"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31719.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:22.044762209Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/07cbb1bd424370671814a862913c99a6e1441588",
        "https://git.kernel.org/stable/c/3bfbf5f0a99c991769ec562721285df7ab69240b",
        "https://git.kernel.org/stable/c/e51f42114abbdf47f29dda43e7826be28907fcd2",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31719.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-31719",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31719.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-31719",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 488354,
  "published_at": "2026-05-01T13:56:13.385+00:00"
}