CVE-2022-50731

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> crypto: akcipher - default implementation for setting a private key<br /> <br /> Changes from v1:<br /> * removed the default implementation from set_pub_key: it is assumed that<br /> an implementation must always have this callback defined as there are<br /> no use case for an algorithm, which doesn&amp;#39;t need a public key<br /> <br /> Many akcipher implementations (like ECDSA) support only signature<br /> verifications, so they don&amp;#39;t have all callbacks defined.<br /> <br /> Commit 78a0324f4a53 ("crypto: akcipher - default implementations for<br /> request callbacks") introduced default callbacks for sign/verify<br /> operations, which just return an error code.<br /> <br /> However, these are not enough, because before calling sign the caller would<br /> likely call set_priv_key first on the instantiated transform (as the<br /> in-kernel testmgr does). This function does not have a default stub, so the<br /> kernel crashes, when trying to set a private key on an akcipher, which<br /> doesn&amp;#39;t support signature generation.<br /> <br /> I&amp;#39;ve noticed this, when trying to add a KAT vector for ECDSA signature to<br /> the testmgr.<br /> <br /> With this patch the testmgr returns an error in dmesg (as it should)<br /> instead of crashing the kernel NULL ptr dereference.