KEYS: fix length validation in keyctl_pkey_params_get_2()

In many cases, keyctl_pkey_params_get_2() is validating the user buffer
lengths against the wrong algorithm properties.  Fix it to check against
the correct properties.

Probably this wasn't noticed before because for all asymmetric keys of
the "public_key" subtype, max_data_size == max_sig_size == max_enc_size
== max_dec_size.  However, this isn't necessarily true for the
"asym_tpm" subtype (it should be, but it's not strictly validated).  Of
course, future key types could have different values as well.

Fixes: 00d60fd3b9 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
This commit is contained in:
Eric Biggers 2022-01-13 12:04:54 -08:00 committed by Jarkko Sakkinen
parent 8335adb8f9
commit c51abd9683

View File

@ -135,15 +135,23 @@ static int keyctl_pkey_params_get_2(const struct keyctl_pkey_params __user *_par
switch (op) {
case KEYCTL_PKEY_ENCRYPT:
if (uparams.in_len > info.max_dec_size ||
uparams.out_len > info.max_enc_size)
return -EINVAL;
break;
case KEYCTL_PKEY_DECRYPT:
if (uparams.in_len > info.max_enc_size ||
uparams.out_len > info.max_dec_size)
return -EINVAL;
break;
case KEYCTL_PKEY_SIGN:
if (uparams.in_len > info.max_data_size ||
uparams.out_len > info.max_sig_size)
return -EINVAL;
break;
case KEYCTL_PKEY_VERIFY:
if (uparams.in_len > info.max_sig_size ||
uparams.out_len > info.max_data_size)
if (uparams.in_len > info.max_data_size ||
uparams.in2_len > info.max_sig_size)
return -EINVAL;
break;
default:
@ -151,7 +159,7 @@ static int keyctl_pkey_params_get_2(const struct keyctl_pkey_params __user *_par
}
params->in_len = uparams.in_len;
params->out_len = uparams.out_len;
params->out_len = uparams.out_len; /* Note: same as in2_len */
return 0;
}