On Fri, Sep 16, 2022 at 07:45:29AM +0200, Nikolaus Voss wrote:
> Commit cd3bc044af48 ("KEYS: encrypted: Instantiate key with user-provided
> decrypted data") added key instantiation with user provided decrypted data.
> The user data is hex-ascii-encoded but was just memcpy'ed to the binary buffer.
> Fix this to use hex2bin instead.
>
> Fixes: cd3bc044af48 ("KEYS: encrypted: Instantiate key with user-provided decrypted data")
> Cc: stable <stable@xxxxxxxxxx>
> Signed-off-by: Nikolaus Voss <nikolaus.voss@xxxxxxxxxxxxxxx>
> ---
> security/keys/encrypted-keys/encrypted.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
> index e05cfc2e49ae..1e313982af02 100644
> --- a/security/keys/encrypted-keys/encrypted.c
> +++ b/security/keys/encrypted-keys/encrypted.c
> @@ -627,7 +627,7 @@ static struct encrypted_key_payload *encrypted_key_alloc(struct key *key,
> pr_err("encrypted key: instantiation of keys using provided decrypted data is disabled since CONFIG_USER_DECRYPTED_DATA is set to false\n");
> return ERR_PTR(-EINVAL);
> }
> - if (strlen(decrypted_data) != decrypted_datalen) {
> + if (strlen(decrypted_data) != decrypted_datalen * 2) {
This looks wrong. What does cap decrypted_data, and why strnlen()
is not used?
> pr_err("encrypted key: decrypted data provided does not match decrypted data length provided\n");
Using pr_err() is probably wrong here and has different prefix
than elsewhere in the file (also most of other uses of pr_err()
are wrong apparently). Nothing bad is really happening.
And who does make any sense of that error message anyway?
For one, I don't understand it.
> return ERR_PTR(-EINVAL);
> }
> @@ -791,8 +791,8 @@ static int encrypted_init(struct encrypted_key_payload *epayload,
> ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv);
> } else if (decrypted_data) {
> get_random_bytes(epayload->iv, ivsize);
> - memcpy(epayload->decrypted_data, decrypted_data,
> - epayload->decrypted_datalen);
> + ret = hex2bin(epayload->decrypted_data, decrypted_data,
> + epayload->decrypted_datalen);
> } else {
> get_random_bytes(epayload->iv, ivsize);
> get_random_bytes(epayload->decrypted_data, epayload->decrypted_datalen);
> --
> 2.34.1
>
BR, Jarkko
