CVE-2026-97591: s390/crypto: Fix handling of EBUSY in PHMAC when req is pushed to crypto engine
In the Linux kernel, the following vulnerability has been resolved:
s390/crypto: Fix handling of EBUSY in PHMAC when req is pushed to crypto engine
When a request is transferred to the engine via cryptotransferhashrequesttoengine() there are two return codes signaling a successful transfer: EINPROGRESS and EBUSY. However the correct handling of EBUSY was missing and has been added as a return code indicating a successful transfer to the crypto engine.
Affected Software
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
The issue applies to Linux kernel systems using the s390 crypto PHMAC path where hash requests are transferred to the crypto engine. The provided information does not identify affected kernel versions or whether this path is enabled by default.
What condition triggers the faulty behavior?
It is triggered when crypto_transfer_hash_request_to_engine() returns EBUSY for a PHMAC request. EBUSY can indicate that transfer to the crypto engine succeeded, but the vulnerable handling did not treat it as a successful transfer.
What should be done if the system uses this path?
Update to a Linux kernel containing the referenced fix. If updating cannot happen immediately, assess whether PHMAC requests are being sent to the s390 crypto engine and whether the installed kernel handles EBUSY as a successful transfer.