In the Linux kernel, the following vulnerability has been resolved:
crypto: akcipher - default implementation for setting a private key
Changes from v1:
* removed the default implementation from set_pub_key: it is assumed that
an implementation must always have this callback defined as there are
no use case for an algorithm, which doesn't need a public key
Many akcipher implementations (like ECDSA) support only signature
verifications, so they don't have all callbacks defined.
Commit 78a0324f4a53 ("crypto: akcipher - default implementations for
request callbacks") introduced default callbacks for sign/verify
operations, which just return an error code.
However, these are not enough, because before calling sign the caller would
likely call set_priv_key first on the instantiated transform (as the
in-kernel testmgr does). This function does not have a default stub, so the
kernel crashes, when trying to set a private key on an akcipher, which
doesn't support signature generation.
I've noticed this, when trying to add a KAT vector for ECDSA signature to
the testmgr.
With this patch the testmgr returns an error in dmesg (as it should)
instead of crashing the kernel NULL ptr dereference.
crypto: akcipher - default implementation for setting a private key
Changes from v1:
* removed the default implementation from set_pub_key: it is assumed that
an implementation must always have this callback defined as there are
no use case for an algorithm, which doesn't need a public key
Many akcipher implementations (like ECDSA) support only signature
verifications, so they don't have all callbacks defined.
Commit 78a0324f4a53 ("crypto: akcipher - default implementations for
request callbacks") introduced default callbacks for sign/verify
operations, which just return an error code.
However, these are not enough, because before calling sign the caller would
likely call set_priv_key first on the instantiated transform (as the
in-kernel testmgr does). This function does not have a default stub, so the
kernel crashes, when trying to set a private key on an akcipher, which
doesn't support signature generation.
I've noticed this, when trying to add a KAT vector for ECDSA signature to
the testmgr.
With this patch the testmgr returns an error in dmesg (as it should)
instead of crashing the kernel NULL ptr dereference.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 24 Dec 2025 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: crypto: akcipher - default implementation for setting a private key Changes from v1: * removed the default implementation from set_pub_key: it is assumed that an implementation must always have this callback defined as there are no use case for an algorithm, which doesn't need a public key Many akcipher implementations (like ECDSA) support only signature verifications, so they don't have all callbacks defined. Commit 78a0324f4a53 ("crypto: akcipher - default implementations for request callbacks") introduced default callbacks for sign/verify operations, which just return an error code. However, these are not enough, because before calling sign the caller would likely call set_priv_key first on the instantiated transform (as the in-kernel testmgr does). This function does not have a default stub, so the kernel crashes, when trying to set a private key on an akcipher, which doesn't support signature generation. I've noticed this, when trying to add a KAT vector for ECDSA signature to the testmgr. With this patch the testmgr returns an error in dmesg (as it should) instead of crashing the kernel NULL ptr dereference. | |
| Title | crypto: akcipher - default implementation for setting a private key | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
Sign in to view the affected projects.
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-12-24T12:22:51.122Z
Reserved: 2025-12-24T12:20:40.331Z
Link: CVE-2022-50731
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-12-24T13:15:59.770
Modified: 2025-12-24T13:15:59.770
Link: CVE-2022-50731
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.