crypto: qat - extend scope of lock in adf_cfg_add_key_value_param()

The function adf_cfg_add_key_value_param() attempts to access and modify
the key value store of the driver without locking.

Extend the scope of cfg->lock to avoid a potential race condition.

Fixes: 92bf269 ("crypto: qat - change behaviour of adf_cfg_add_key_value_param()")
Signed-off-by: Nivas Varadharajan Mugunthakumar <nivasx.varadharajan.mugunthakumar@intel.com>
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Author: nivasvm

drivers/crypto/intel/qat/qat_common/adf_cfg.c

@@ -290,17 +290,19 @@ int adf_cfg_add_key_value_param(struct adf_accel_dev *accel_dev,
 	 * 3. if the key exists with the same value, then return without doing
 	 *    anything (the newly created key_val is freed).
 	 */
+	down_write(&cfg->lock);
 	if (!adf_cfg_key_val_get(accel_dev, section_name, key, temp_val)) {
 		if (strncmp(temp_val, key_val->val, sizeof(temp_val))) {
 			adf_cfg_keyval_remove(key, section);
 		} else {
 			kfree(key_val);
-			return 0;
+			goto out;
 		}
 	}
 
-	down_write(&cfg->lock);
 	adf_cfg_keyval_add(key_val, section);
+
+out:
 	up_write(&cfg->lock);
 	return 0;
 }