RE: [PATCH v2] tools/hv: Add memory allocation check in hv_fcopy_start

[Dexuan Cui <decui@xxxxxxxxxxxxx>]

> From: Zhu Jun <zhujun2@xxxxxxxxxxxxxxxxxxxx>
> Sent: Wednesday, August 28, 2024 7:45 PM
> @@ -296,6 +296,18 @@ static int hv_fcopy_start(struct hv_start_fcopy
> *smsg_in)
>         file_name = (char *)malloc(file_size * sizeof(char));
>         path_name = (char *)malloc(path_size * sizeof(char));
> 
> +    if (!file_name) {
> +        free(file_name);
> +        syslog(LOG_ERR, "Can't allocate file_name memory!");
> +        exit(EXIT_FAILURE);
> +    }
> +
> +    if (!path_name) {
> +        free(path_name);
> +        syslog(LOG_ERR, "Can't allocate path_name memory!");
> +        exit(EXIT_FAILURE);
> +    }

If we're calling exit() just 2 lines later, it doesn't make a lot of sense
to call free().

How about this:

@@ -296,6 +296,12 @@ static int hv_fcopy_start(struct hv_start_fcopy *smsg_in)
        file_name = (char *)malloc(file_size * sizeof(char));
        path_name = (char *)malloc(path_size * sizeof(char));

+       if (!file_name || !path_name) {
+               free(file_name);
+               free(path_name);
+ 	   syslog(LOG_ERR, "Can't allocate memory for file name and/or path name");
+               return HV_E_FAIL;
+       }

Note: free(NULL) is valid (refer to "man 3 free").