Re: [PATCH] libsepol: create new keys with copy of 'name' variable

[James Carter <jwcart2@tycho.nsa.gov>]

On 08/25/2015 10:05 AM, Petr Lautrbach wrote:
> sepol_*_key_create functions, which create keys based only on name, copy only
> a pointer to a new key. This pointer doesn't need to be valid during the new key
> lifetime therefore it's necessary to create a copy of it.
>
> E.g. Python 3 SWIG bindings temporarily allocate memory needed for
> PyUnicodeObject->char * conversion. This memory is deallocated shortly
> after underlying C function returns.
>
> Patch-by: Michal Srb <msrb@redhat.com>
> Signed-off-by: Petr Lautrbach <plautrba@redhat.com>
> ---
>   libsepol/src/boolean_record.c | 7 +++++--
>   libsepol/src/iface_record.c   | 7 +++++--
>   libsepol/src/user_record.c    | 7 +++++--
>   3 files changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/libsepol/src/boolean_record.c b/libsepol/src/boolean_record.c
> index 8b64413..0d139ac 100644
> --- a/libsepol/src/boolean_record.c
> +++ b/libsepol/src/boolean_record.c
> @@ -25,12 +25,14 @@ int sepol_bool_key_create(sepol_handle_t * handle,
>   	sepol_bool_key_t *tmp_key =
>   	    (sepol_bool_key_t *) malloc(sizeof(struct sepol_bool_key));
>
> -	if (!tmp_key) {
> +	char *tmp_name = strdup(name);
> +
> +	if (!tmp_key || !tmp_name) {
>   		ERR(handle, "out of memory, " "could not create boolean key");
>   		return STATUS_ERR;
>   	}
>

Need to free tmp_key if it is allocated, but the strdup for tmp_name fails. And 
vice versa.


> -	tmp_key->name = name;
> +	tmp_key->name = tmp_name;
>
>   	*key_ptr = tmp_key;
>   	return STATUS_SUCCESS;
> @@ -62,6 +64,7 @@ int sepol_bool_key_extract(sepol_handle_t * handle,
>
>   void sepol_bool_key_free(sepol_bool_key_t * key)
>   {
> +	free(key->name);
>   	free(key);
>   }
>
> diff --git a/libsepol/src/iface_record.c b/libsepol/src/iface_record.c
> index 09adeb7..4315238 100644
> --- a/libsepol/src/iface_record.c
> +++ b/libsepol/src/iface_record.c
> @@ -31,12 +31,14 @@ int sepol_iface_key_create(sepol_handle_t * handle,
>   	sepol_iface_key_t *tmp_key =
>   	    (sepol_iface_key_t *) malloc(sizeof(sepol_iface_key_t));
>
> -	if (!tmp_key) {
> +	char *tmp_name = strdup(name);
> +
> +	if (!tmp_key || !tmp_name) {
>   		ERR(handle, "out of memory, could not create interface key");
>   		return STATUS_ERR;
>   	}
>

Same here.


> -	tmp_key->name = name;
> +	tmp_key->name = tmp_name;
>
>   	*key_ptr = tmp_key;
>   	return STATUS_SUCCESS;
> @@ -68,6 +70,7 @@ int sepol_iface_key_extract(sepol_handle_t * handle,
>
>   void sepol_iface_key_free(sepol_iface_key_t * key)
>   {
> +	free(key->name);
>   	free(key);
>   }
>
> diff --git a/libsepol/src/user_record.c b/libsepol/src/user_record.c
> index c59c54b..dfc66e5 100644
> --- a/libsepol/src/user_record.c
> +++ b/libsepol/src/user_record.c
> @@ -34,13 +34,15 @@ int sepol_user_key_create(sepol_handle_t * handle,
>   	sepol_user_key_t *tmp_key =
>   	    (sepol_user_key_t *) malloc(sizeof(sepol_user_key_t));
>
> -	if (!tmp_key) {
> +	char *tmp_name = strdup(name);
> +
> +	if (!tmp_key || !tmp_name) {
>   		ERR(handle, "out of memory, "
>   		    "could not create selinux user key");
>   		return STATUS_ERR;
>   	}
>

And here.

> -	tmp_key->name = name;
> +	tmp_key->name = tmp_name;
>
>   	*key_ptr = tmp_key;
>   	return STATUS_SUCCESS;
> @@ -71,6 +73,7 @@ int sepol_user_key_extract(sepol_handle_t * handle,
>
>   void sepol_user_key_free(sepol_user_key_t * key)
>   {
> +	free(key->name);
>   	free(key);
>   }
>
>


-- 
James Carter <jwcart2@tycho.nsa.gov>
National Security Agency