Re: [PATCH 062/104] virtiofsd: Handle hard reboot

[Daniel P . Berrangé]

On Thu, Dec 12, 2019 at 04:38:22PM +0000, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
> 
> Handle a
>   mount
>   hard reboot (without unmount)
>   mount
> 
> we get another 'init' which FUSE doesn't normally expect.
> 
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> ---
>  tools/virtiofsd/fuse_lowlevel.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
> index 2d1d1a2e59..45125ef66a 100644
> --- a/tools/virtiofsd/fuse_lowlevel.c
> +++ b/tools/virtiofsd/fuse_lowlevel.c
> @@ -2436,7 +2436,21 @@ void fuse_session_process_buf_int(struct fuse_session 
> *se,
>              goto reply_err;
>          }
>      } else if (in->opcode == FUSE_INIT || in->opcode == CUSE_INIT) {
> -        goto reply_err;
> +        if (fuse_lowlevel_is_virtio(se)) {
> +            /*
> +             * TODO: This is after a hard reboot typically, we need to do
> +             * a destroy, but we can't reply to this request yet so
> +             * we can't use do_destroy
> +             */
> +            fuse_log(FUSE_LOG_DEBUG, "%s: reinit\n", __func__);
> +            se->got_destroy = 1;
> +            se->got_init = 0;
> +            if (se->op.destroy) {
> +                se->op.destroy(se->userdata);
> +            }
> +        } else {
> +            goto reply_err;
> +        }

In doing this, is there any danger we're exposed to from a malicious
guest which does

   mount
   mount

without a reboot in between ?

I'm thinking not so if its ok, then

 Reviewed-by: Daniel P. Berrangé <address@hidden>
 

Regards,
Daniel
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