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KEYS: trusted: dcp: fix NULL dereference in AEAD crypto operation

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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: 0e28bf61a5 ("KEYS: trusted: dcp: fix leak of blob encryption key")
Reported-by: Parthiban N <parthiban@linumiz.com>
Closes: https://lore.kernel.org/keyrings/254d3bb1-6dbc-48b4-9c08-77df04baee2f@linumiz.com/
Signed-off-by: David Gstir <david@sigma-star.at>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
This commit is contained in:
David Gstir 2024-10-29 12:34:01 +01:00 committed by Jarkko Sakkinen
parent 4a74da044e
commit 04de7589e0
1 changed files with 5 additions and 4 deletions
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9
security/keys/trusted-keys/trusted_dcp.c
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@ -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);