Re: [PATCH linux-cr] always restore msg_msg label

[Oren Laadan <orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>]

In v20-rc1.

Serge E. Hallyn wrote:
> Hi Oren,
> 
> In comparing your ckpt-v19-dev-serge branch to my local one I
> noticed this patch was missing, then realized I hadn't sent it
> separately, but only inline with a response to Nathan.
> 
> Please do apply.
> 
> Without this patch, selinux labels will not be restored on msg_msg's in
> message queues (because we didn't send the restored msg_msg through
> msgsnd), and the restored task won't have the permission to receive the
> messages.
> 
> As I mentioned in that thread, simply re-routing the restored
> msg_msg through msgsnd doesn't really suffice because the msg_msg
> label is calculated as a product of the msgq and sending task
> labels, and the latter may have already changed.
> 
> thanks,
> -serge
> 
> Signed-off-by: Serge E. Hallyn <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
> ---
>  security/security.c |    4 +++-
>  1 files changed, 3 insertions(+), 1 deletions(-)
> 
> diff --git a/security/security.c b/security/security.c
> index 28db976..2b147cf 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1524,7 +1524,9 @@ int security_restore_obj(struct ckpt_ctx *ctx, void *v, int sectype,
>  
>  	/* return if caller didn't want to restore checkpointed labels */
>  	if (!(ctx->uflags & RESTART_KEEP_LSM))
> -		return 0;
> +		/* though msg_msg label must always be restored */
> +		if (sectype != CKPT_SECURITY_MSG_MSG)
> +			return 0;
>  
>  	l = ckpt_obj_fetch(ctx, secref, CKPT_OBJ_SECURITY);
>  	if (IS_ERR(l))