Re: [PATCH 1/3] libsepol: initialize tmp_key->ibdev_name if its allocation failed

[jwcart2]

On 03/05/2018 05:58 PM, Nicolas Iooss wrote:

In sepol_ibendport_key_create(), if sepol_ibendport_alloc_ibdev_name()
fails to allocate tmp_key->ibdev_name, sepol_ibendport_key_free() is
called to free the memory associated with tmp_key, which results in
free() being called on uninitialized tmp_key->ibdev_name.

This issue is reported by clang's static analyzer with the following
message:

 ibendport_record.c:115:2: warning: 1st function call argument is an
 uninitialized value
 free(key->ibdev_name);
 ^

Signed-off-by: Nicolas Iooss 
---
  libsepol/src/ibendport_record.c | 4 +++-
  1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libsepol/src/ibendport_record.c b/libsepol/src/ibendport_record.c
index 912aeb536fd9..8285a9d6ffcf 100644
--- a/libsepol/src/ibendport_record.c
+++ b/libsepol/src/ibendport_record.c
@@ -62,8 +62,10 @@ int sepol_ibendport_key_create(sepol_handle_t *handle,
goto omem;
}
  
-	if (sepol_ibendport_alloc_ibdev_name(handle, &tmp_key->ibdev_name) < 0)

+   if (sepol_ibendport_alloc_ibdev_name(handle, &tmp_key->ibdev_name) < 0) 
{
+   tmp_key->ibdev_name = NULL;
goto err;
+   }
  
  	strncpy(tmp_key->ibdev_name, ibdev_name, IB_DEVICE_NAME_MAX);

tmp_key->port = port;



It seems to be that a better way to fix this is to modify 
sepol_ibendport_alloc_ibdev_name(), so that the result of the calloc is assigned 
to *ibdev_name. That way if the calloc fails, tmp_key->ibdev_name will be set to 
NULL automatically.



--
James Carter 
National Security Agency

Re: [PATCH 1/3] libsepol: initialize tmp_key->ibdev_name if its allocation failed

[Stephen Smalley]

On 03/05/2018 05:58 PM, Nicolas Iooss wrote:
> In sepol_ibendport_key_create(), if sepol_ibendport_alloc_ibdev_name()
> fails to allocate tmp_key->ibdev_name, sepol_ibendport_key_free() is
> called to free the memory associated with tmp_key, which results in
> free() being called on uninitialized tmp_key->ibdev_name.
> 
> This issue is reported by clang's static analyzer with the following
> message:
> 
> ibendport_record.c:115:2: warning: 1st function call argument is an
> uninitialized value
> free(key->ibdev_name);
> ^
> 
> Signed-off-by: Nicolas Iooss 

Acked-by: Stephen Smalley 

> ---
>  libsepol/src/ibendport_record.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/libsepol/src/ibendport_record.c b/libsepol/src/ibendport_record.c
> index 912aeb536fd9..8285a9d6ffcf 100644
> --- a/libsepol/src/ibendport_record.c
> +++ b/libsepol/src/ibendport_record.c
> @@ -62,8 +62,10 @@ int sepol_ibendport_key_create(sepol_handle_t *handle,
>   goto omem;
>   }
>  
> - if (sepol_ibendport_alloc_ibdev_name(handle, &tmp_key->ibdev_name) < 0)
> + if (sepol_ibendport_alloc_ibdev_name(handle, &tmp_key->ibdev_name) < 0) 
> {
> + tmp_key->ibdev_name = NULL;
>   goto err;
> + }
>  
>   strncpy(tmp_key->ibdev_name, ibdev_name, IB_DEVICE_NAME_MAX);
>   tmp_key->port = port;
>