Bluetooth: Use kzfree instead of kfree in security manager

Within the security manager, it makes sense to use kzfree instead of
kfree for all data structures. This ensures that no key material leaks
by accident.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 9155840..a2be6fc 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -681,9 +681,9 @@
 	complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags);
 	mgmt_smp_complete(hcon, complete);
 
-	kfree(smp->csrk);
-	kfree(smp->slave_csrk);
-	kfree(smp->link_key);
+	kzfree(smp->csrk);
+	kzfree(smp->slave_csrk);
+	kzfree(smp->link_key);
 
 	crypto_free_blkcipher(smp->tfm_aes);
 	crypto_free_hash(smp->tfm_cmac);
@@ -717,7 +717,7 @@
 	}
 
 	chan->data = NULL;
-	kfree(smp);
+	kzfree(smp);
 	hci_conn_drop(hcon);
 }
 
@@ -1097,13 +1097,13 @@
 		return;
 
 	if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) {
-		kfree(smp->link_key);
+		kzfree(smp->link_key);
 		smp->link_key = NULL;
 		return;
 	}
 
 	if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) {
-		kfree(smp->link_key);
+		kzfree(smp->link_key);
 		smp->link_key = NULL;
 		return;
 	}
@@ -1300,7 +1300,7 @@
 	smp->tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
 	if (IS_ERR(smp->tfm_aes)) {
 		BT_ERR("Unable to create ECB crypto context");
-		kfree(smp);
+		kzfree(smp);
 		return NULL;
 	}
 
@@ -1308,7 +1308,7 @@
 	if (IS_ERR(smp->tfm_cmac)) {
 		BT_ERR("Unable to create CMAC crypto context");
 		crypto_free_blkcipher(smp->tfm_aes);
-		kfree(smp);
+		kzfree(smp);
 		return NULL;
 	}