CVE-2022-50731
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.
EPSS (Exploit Prediction Scoring System)
EPSS (Exploit Prediction Scoring System)
Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.