Commit 04de7589 authored by David Gstir's avatar David Gstir Committed by Jarkko Sakkinen
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KEYS: trusted: dcp: fix NULL dereference in AEAD crypto operation 



When sealing or unsealing a key blob we currently do not wait for
the AEAD cipher operation to finish and simply return after submitting
the request. If there is some load on the system we can exit before
the cipher operation is done and the buffer we read from/write to
is already removed from the stack. This will e.g. result in NULL
pointer dereference errors in the DCP driver during blob creation.

Fix this by waiting for the AEAD cipher operation to finish before
resuming the seal and unseal calls.

Cc: stable@vger.kernel.org # v6.10+
Fixes: 0e28bf61 ("KEYS: trusted: dcp: fix leak of blob encryption key")
Reported-by: default avatarParthiban N <parthiban@linumiz.com>
Closes: https://lore.kernel.org/keyrings/254d3bb1-6dbc-48b4-9c08-77df04baee2f@linumiz.com/


Signed-off-by: default avatarDavid Gstir <david@sigma-star.at>
Reviewed-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
parent 4a74da04

security/keys/trusted-keys/trusted_dcp.c

+5 −4
Original line number Diff line number Diff line
@@ -133,6 +133,7 @@ static int do_aead_crypto(u8 *in, u8 *out, size_t len, u8 *key, u8 *nonce, 
	struct scatterlist src_sg, dst_sg;

	struct crypto_aead *aead;

	int ret;

	DECLARE_CRYPTO_WAIT(wait);



	aead = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);

	if (IS_ERR(aead)) {
@@ -163,8 +164,8 @@ static int do_aead_crypto(u8 *in, u8 *out, size_t len, u8 *key, u8 *nonce, 
	}



	aead_request_set_crypt(aead_req, &src_sg, &dst_sg, len, nonce);

	aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL,

				  NULL);

	aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_SLEEP,

				  crypto_req_done, &wait);

	aead_request_set_ad(aead_req, 0);



	if (crypto_aead_setkey(aead, key, AES_KEYSIZE_128)) {
@@ -174,9 +175,9 @@ static int do_aead_crypto(u8 *in, u8 *out, size_t len, u8 *key, u8 *nonce, 
	}



	if (do_encrypt)

		ret = crypto_aead_encrypt(aead_req);

		ret = crypto_wait_req(crypto_aead_encrypt(aead_req), &wait);

	else

		ret = crypto_aead_decrypt(aead_req);

		ret = crypto_wait_req(crypto_aead_decrypt(aead_req), &wait);



free_req:

	aead_request_free(aead_req);