crypto: possible NULL reference

From: Randy Dunlap
Date: Tue Mar 30 2021 - 00:12:36 EST


As I was trying to document "fips=<integer", I noticed this.

In crypto/ecc.c, ecc_get_curve() can return NULL:

const struct ecc_curve *ecc_get_curve(unsigned int curve_id)
{
switch (curve_id) {
/* In FIPS mode only allow P256 and higher */
case ECC_CURVE_NIST_P192:
return fips_enabled ? NULL : &nist_p192;
case ECC_CURVE_NIST_P256:
return &nist_p256;
case ECC_CURVE_NIST_P384:
return &nist_p384;
default:
return NULL;
}
}

but when its return value is passed to
static int __ecc_is_key_valid(const struct ecc_curve *curve,
const u64 *private_key, unsigned int ndigits)

the use of <curve> here is not checked for NULL or not NULL
before it is used. Nor is the use of <curve> in most other functions
in ecc.c.


Is there something else protecting the improper use of <curve>
in these cases? or is a patch warranted?


thanks.
--
~Randy