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.

Timeline

1. May 1, 2026, 1:56 PM UTCCVE published
2. Oct 16, 2026, 3:12 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. Oct 19, 2026, 7:06 PM UTCRecord last updated

Affected versions

• Linux Linux

  From d1775a177f7f38156d541c8a3e3c91eaa6e69699 · fixed in 07cbb1bd424370671814a862913c99a6e1441588; From d1775a177f7f38156d541c8a3e3c91eaa6e69699 · fixed in e51f42114abbdf47f29dda43e7826be28907fcd2; From d1775a177f7f38156d541c8a3e3c91eaa6e69699 · fixed in 3bfbf5f0a99c991769ec562721285df7ab69240b

• Linux Linux

  6.15

• KernelLinux

  From 6.15.0 · fixed in 6.18.25; From 6.19.0 · fixed in 7.0.2

References 3