On Wed, Oct 15, 2014 at 10:05:46AM -0700, Andy Lutomirski wrote: > On Wed, Oct 15, 2014 at 8:05 AM, Seth Forshee > <seth.forshee@xxxxxxxxxxxxx> wrote: > > On Wed, Oct 15, 2014 at 07:49:39AM -0700, Andy Lutomirski wrote: > >> On 10/14/2014 07:25 AM, Seth Forshee wrote: > >> > Update fuse to translate uids and gids to/from the user namspace > >> > of the process servicing requests on /dev/fuse. Any ids which do > >> > not map into the namespace will result in errors. inodes will > >> > also be marked bad when unmappable ids are received from > >> > userspace. > >> > > >> > Due to security concerns the namespace used should be fixed, > >> > otherwise a user might be able to gain elevated privileges or > >> > influence processes that the user would otherwise be unable to > >> > manipulate. Thus the namespace of the mounting process is used > >> > for all translations, and this namespace is required to be the > >> > same as the one in use when /dev/fuse was opened. > >> > > >> > >> I'm not sure that this is necessary if my nosuid patch goes in, but I > >> also don't think it makes any sense to hold this up while we find a > >> perfect solution. > >> > >> Is there a decent way to extend this to different translation schemes in > >> the future (e.g. a flag at fs setup that could be used)? > > > > I think it would be possible to relax the translation scheme > > restrictions in the future, certainly that's easier than tightening down > > a looser restriction. I still favor picking one namespace to use for > > translation (surely that's how it would work with other filesystems > > anyway) rather than using the current namespace during /dev/fuse I/O. I > > did an implementation using the latter technique, and it's far more > > complex with no benefits that I can see. > > Long term, I think we'll want more flexible translations for > filesystems on removable media, even when both the mounter and the > accessing process are in the init user namespace. But this can wait. You've piqued my interest. What are you thinking of which would require this flexibility? Thanks, Seth -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
