Re: [PATCH] tools/virtiofsd: Add fstatfs64 syscall to the seccomp allowlist

[Vivek Goyal]

On Tue, Sep 14, 2021 at 02:32:14PM +0200, Thomas Huth wrote:
> The virtiofsd currently crashes on s390x when doing something like
> this in the guest:
> 
>  mkdir -p /mnt/myfs
>  mount -t virtiofs myfs /mnt/myfs
>  touch /mnt/myfs/foo.txt
>  stat -f /mnt/myfs/foo.txt
> 
> The problem is that the fstatfs64 syscall is called in this case
> from the virtiofsd. We have to put it on the seccomp allowlist to
> avoid that the daemon gets killed in this case.
> 
> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2001728
> Suggested-by: Vivek Goyal <vgoyal@redhat.com>
> Signed-off-by: Thomas Huth <thuth@redhat.com>

Reviewed-by: Vivek Goyal <vgoyal@redhat.com>

Thanks Thomas for the patch.

Vivek
> ---
>  tools/virtiofsd/passthrough_seccomp.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/tools/virtiofsd/passthrough_seccomp.c 
> b/tools/virtiofsd/passthrough_seccomp.c
> index f49ed94b5e..a3ce9f898d 100644
> --- a/tools/virtiofsd/passthrough_seccomp.c
> +++ b/tools/virtiofsd/passthrough_seccomp.c
> @@ -51,6 +51,7 @@ static const int syscall_allowlist[] = {
>      SCMP_SYS(fsetxattr),
>      SCMP_SYS(fstat),
>      SCMP_SYS(fstatfs),
> +    SCMP_SYS(fstatfs64),
>      SCMP_SYS(fsync),
>      SCMP_SYS(ftruncate),
>      SCMP_SYS(futex),
> -- 
> 2.27.0
>