On Thu, Feb 23, 2017 at 4:02 PM, Eric Blake <ebl...@redhat.com> wrote: > On 02/20/2017 08:40 AM, Greg Kurz wrote: >> All operations dealing with extended attributes are vulnerable to symlink >> attacks because they use path-based syscalls which can traverse symbolic >> links while walking through the dirname part of the path. >> >> The solution is to introduce helpers based on opendir_nofollow(). This >> calls for "at" versions of the extended attribute syscalls, which don't >> exist unfortunately. This patch implement them by simulating the "at" >> behavior with fchdir(). Since the current working directory is process >> wide, and we don't want to confuse another thread in QEMU, all the work >> is done in a separate process. > > Can you emulate *at using /proc/fd/nnn/xyz?
I don't know much about QEMU internals, but QEMU supports running in a chroot using the -chroot option, right? Does that already require procfs to be mounted inside the chroot?
