Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-05-01T00:00:00 kernel: crypto: krb5enc - fix async decrypt skipping hash verification 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CWE-325

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.

A flaw was found in the `krb5enc` module of the Linux kernel's crypto subsystem. When performing asynchronous decryption, the `krb5enc_dispatch_decrypt()` function incorrectly bypasses the integrity verification (hash check). This issue occurs because the `skcipher` completion handler signals completion without executing the necessary hash verification, potentially allowing an attacker to manipulate data without detection.

Kerberos5 transform async decrypt must not skip hash verification; skipping breaks integrity guarantees for `krb5enc` users. Red Hat recommends patched kernels for IPsec or other consumers of this crypto template. Red Hat Enterprise Linux 10 Affected kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Affected kernel Red Hat Enterprise Linux 9 Affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-31719 https://nvd.nist.gov/vuln/detail/CVE-2026-31719 https://lore.kernel.org/linux-cve-announce/2026050125-CVE-2026-31719-3da7@gregkh/T