Re: [PATCH v3 24/24] AppArmor: Remove the exclusive flag

[Kees Cook <keescook@chromium.org>]

On Fri, Jun 21, 2019 at 11:52:33AM -0700, Casey Schaufler wrote:
> With the inclusion of the "display" process attribute
> mechanism AppArmor no longer needs to be treated as an
> "exclusive" security module. Remove the flag that indicates
> it is exclusive. Remove the stub getpeersec_dgram AppArmor
> hook as it has no effect in the single LSM case and
> interferes in the multiple LSM case.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  security/apparmor/lsm.c | 20 +-------------------
>  1 file changed, 1 insertion(+), 19 deletions(-)
> 
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index dcbbefbd95ff..c4365434f10b 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -1082,22 +1082,6 @@ static int apparmor_socket_getpeersec_stream(struct socket *sock,
>  	return error;
>  }
>  
> -/**
> - * apparmor_socket_getpeersec_dgram - get security label of packet
> - * @sock: the peer socket
> - * @skb: packet data
> - * @secid: pointer to where to put the secid of the packet
> - *
> - * Sets the netlabel socket state on sk from parent
> - */
> -static int apparmor_socket_getpeersec_dgram(struct socket *sock,
> -					    struct sk_buff *skb, u32 *secid)
> -
> -{
> -	/* TODO: requires secid support */
> -	return -ENOPROTOOPT;
> -}
> -
>  /**
>   * apparmor_sock_graft - Initialize newly created socket
>   * @sk: child sock
> @@ -1196,8 +1180,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
>  #endif
>  	LSM_HOOK_INIT(socket_getpeersec_stream,
>  		      apparmor_socket_getpeersec_stream),
> -	LSM_HOOK_INIT(socket_getpeersec_dgram,
> -		      apparmor_socket_getpeersec_dgram),
>  	LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
>  #ifdef CONFIG_NETWORK_SECMARK
>  	LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
> @@ -1709,7 +1691,7 @@ static int __init apparmor_init(void)
>  
>  DEFINE_LSM(apparmor) = {
>  	.name = "apparmor",
> -	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
> +	.flags = LSM_FLAG_LEGACY_MAJOR,
>  	.enabled = &apparmor_enabled,
>  	.blobs = &apparmor_blob_sizes,
>  	.init = apparmor_init,
> -- 
> 2.20.1
> 

-- 
Kees Cook