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path: root/security/integrity/evm/evm_crypto.c
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Diffstat (limited to 'security/integrity/evm/evm_crypto.c')
-rw-r--r--security/integrity/evm/evm_crypto.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index 5dd5b140242..8738deff26f 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -27,20 +27,35 @@ static int evmkey_len = MAX_KEY_SIZE;
struct crypto_shash *hmac_tfm;
+static DEFINE_MUTEX(mutex);
+
static struct shash_desc *init_desc(void)
{
int rc;
struct shash_desc *desc;
if (hmac_tfm == NULL) {
+ mutex_lock(&mutex);
+ if (hmac_tfm)
+ goto out;
hmac_tfm = crypto_alloc_shash(evm_hmac, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(hmac_tfm)) {
pr_err("Can not allocate %s (reason: %ld)\n",
evm_hmac, PTR_ERR(hmac_tfm));
rc = PTR_ERR(hmac_tfm);
hmac_tfm = NULL;
+ mutex_unlock(&mutex);
+ return ERR_PTR(rc);
+ }
+ rc = crypto_shash_setkey(hmac_tfm, evmkey, evmkey_len);
+ if (rc) {
+ crypto_free_shash(hmac_tfm);
+ hmac_tfm = NULL;
+ mutex_unlock(&mutex);
return ERR_PTR(rc);
}
+out:
+ mutex_unlock(&mutex);
}
desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac_tfm),
@@ -51,11 +66,7 @@ static struct shash_desc *init_desc(void)
desc->tfm = hmac_tfm;
desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
- rc = crypto_shash_setkey(hmac_tfm, evmkey, evmkey_len);
- if (rc)
- goto out;
rc = crypto_shash_init(desc);
-out:
if (rc) {
kfree(desc);
return ERR_PTR(rc);