Re: [RESEND PATCH v1] xen/xsm: flask: restore sidtab state on policy load failure

["Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>]

Hey Sergiy,

Apologies for not getting a response on the first send, been a bit 
preoccupied with preparing customer delivery.
On 10/2/26 5:26 AM, Sergiy Kibrik wrote:
> Error path of failed sidtab_map() leaves global sidtab in shutdown state and
> from that point system is unable to allocate new SIDs in 
> sidtab_context_to_sid().
> To restore sidtab state new function sidtab_activate() is introduced, which only
> resets shutdown flag, rewinding effect of sidtab_shutdown().
>
> Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>
> ---
> New function is not strictly required, this also can be achieved just by
> doing sidtab_set(&sidtab, &sidtab), but this way we would rely on its
> undocumented internal behaviour.
> ---
>   xen/xsm/flask/ss/services.c | 1 +
>   xen/xsm/flask/ss/sidtab.c   | 7 +++++++
>   xen/xsm/flask/ss/sidtab.h   | 1 +
>   3 files changed, 9 insertions(+)
>
> diff --git a/xen/xsm/flask/ss/services.c b/xen/xsm/flask/ss/services.c
> index 35ad1034ca..f5cee1e0b0 100644
> --- a/xen/xsm/flask/ss/services.c
> +++ b/xen/xsm/flask/ss/services.c
> @@ -1427,6 +1427,7 @@ int security_load_policy(const void *data, size_t len)
>       if ( sidtab_map(&sidtab, clone_sid, &newsidtab) )
>       {
>           rc = -ENOMEM;
> +        sidtab_activate(&sidtab);
>           goto err;
>       }
>   
> diff --git a/xen/xsm/flask/ss/sidtab.c b/xen/xsm/flask/ss/sidtab.c
> index 69fc3389b3..5d1653cd02 100644
> --- a/xen/xsm/flask/ss/sidtab.c
> +++ b/xen/xsm/flask/ss/sidtab.c
> @@ -314,6 +314,13 @@ void sidtab_set(struct sidtab *dst, struct sidtab *src)
>       SIDTAB_UNLOCK(src);
>   }
>   
> +void sidtab_activate(struct sidtab *s)
> +{
> +    SIDTAB_LOCK(s);
> +    s->shutdown = 0;
> +    SIDTAB_UNLOCK(s);
> +}
> +
I think calling this sidtab_activate is a bit misleading, as activation 
is really the success path of security_load_policy. Perhaps 
sidtab_cancel_shutdown?

If you're not opposed to the rename, then on respin,

Acked-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxx>