Re: [Qemu-devel] [PATCH v3 1/6] seccomp: changing from whitelist to blacklist

[Thomas Huth]

On 28.07.2017 14:10, Eduardo Otubo wrote:
> This patch changes the default behavior of the seccomp filter from
> whitelist to blacklist. By default now all system calls are allowed and
> a small black list of definitely forbidden ones was created.
> 
> Signed-off-by: Eduardo Otubo <address@hidden>
> ---
>  qemu-seccomp.c | 256 
> +++++++--------------------------------------------------
>  vl.c           |   5 +-
>  2 files changed, 32 insertions(+), 229 deletions(-)
> 
> diff --git a/qemu-seccomp.c b/qemu-seccomp.c
> index df75d9c471..f8877b07b5 100644
> --- a/qemu-seccomp.c
> +++ b/qemu-seccomp.c
> @@ -31,229 +31,29 @@ struct QemuSeccompSyscall {
>      uint8_t priority;
>  };
[...]
> +static const struct QemuSeccompSyscall blacklist[] = {
> +    { SCMP_SYS(reboot), 255 },
> +    { SCMP_SYS(swapon), 255 },
> +    { SCMP_SYS(swapoff), 255 },
> +    { SCMP_SYS(syslog), 255 },
> +    { SCMP_SYS(mount), 255 },
> +    { SCMP_SYS(umount), 255 },
> +    { SCMP_SYS(kexec_load), 255 },
> +    { SCMP_SYS(afs_syscall), 255 },
> +    { SCMP_SYS(break), 255 },
> +    { SCMP_SYS(ftime), 255 },
> +    { SCMP_SYS(getpmsg), 255 },
> +    { SCMP_SYS(gtty), 255 },
> +    { SCMP_SYS(lock), 255 },
> +    { SCMP_SYS(mpx), 255 },
> +    { SCMP_SYS(prof), 255 },
> +    { SCMP_SYS(profil), 255 },
> +    { SCMP_SYS(putpmsg), 255 },
> +    { SCMP_SYS(security), 255 },
> +    { SCMP_SYS(stty), 255 },
> +    { SCMP_SYS(tuxcall), 255 },
> +    { SCMP_SYS(ulimit), 255 },
> +    { SCMP_SYS(vserver), 255 },
>  };

Does it makes sense to still keep the priority field? Everything is now
marked with the value 255 and I currently fail to see the point of
priorities when using blacklisting ... so maybe just get rid of it?

 Thomas