[PATCH net] netlabel: cope with NULL catmap

[Paul Moore]

On Tue, May 12, 2020 at 8:44 AM Paolo Abeni <pabeni at redhat.com> wrote:
>
> The cipso and calipso code can set the MLS_CAT attribute on
> successful parsing, even if the corresponding catmap has
> not been allocated, as per current configuration and external
> input.
>
> Later, selinux code tries to access the catmap if the MLS_CAT flag
> is present via netlbl_catmap_getlong(). That may cause null ptr
> dereference while processing incoming network traffic.
>
> Address the issue setting the MLS_CAT flag only if the catmap is
> really allocated. Additionally let netlbl_catmap_getlong() cope
> with NULL catmap.
>
> Reported-by: Matthew Sheets <matthew.sheets at gd-ms.com>
> Fixes: 4b8feff251da ("netlabel: fix the horribly broken catmap functions")
> Fixes: ceba1832b1b2 ("calipso: Set the calipso socket label to match the secattr.")
> Signed-off-by: Paolo Abeni <pabeni at redhat.com>
> ---
>  net/ipv4/cipso_ipv4.c        | 6 ++++--
>  net/ipv6/calipso.c           | 3 ++-
>  net/netlabel/netlabel_kapi.c | 6 ++++++
>  3 files changed, 12 insertions(+), 3 deletions(-)

Seems reasonable to me, thanks Paolo.

Acked-by: Paul Moore <paul at paul-moore.com>

-- 
paul moore
www.paul-moore.com