CVE-2022-50731
crypto: akcipher - default implementation for setting a private key
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.
INFO
Published Date :
Dec. 24, 2025, 1:15 p.m.
Last Modified :
Dec. 24, 2025, 1:15 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2022-50731
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply the patch to the Linux kernel.
- Update the Linux kernel to the latest stable version.
- Recompile the kernel with the patch applied.
- Test the crypto subsystem after applying the patch.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2022-50731.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2022-50731 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2022-50731
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2022-50731 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2022-50731 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Dec. 24, 2025
Action Type Old Value New Value 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. Added Reference https://git.kernel.org/stable/c/779a9930f3e152c82699feb389a0e6d6644e747e Added Reference https://git.kernel.org/stable/c/85bc736a18b872f54912e8bb70682d11770aece0 Added Reference https://git.kernel.org/stable/c/95c4e20adc3ea00d1594a2a05d9b187ed12ffa8e Added Reference https://git.kernel.org/stable/c/a1354bdd191d533211b7cb723aa76a66f516f197 Added Reference https://git.kernel.org/stable/c/bc155c6c188c2f0c5749993b1405673d25a80389 Added Reference https://git.kernel.org/stable/c/f9058178597059d6307efe96a7916600f8ede08c