Re: [PATCH RESEND v2 00/19] Support fuse mounts in user namespaces
From: Seth Forshee
Date: Mon Jan 25 2016 - 14:48:32 EST
On Mon, Jan 04, 2016 at 12:03:39PM -0600, Seth Forshee wrote:
> These patches implement support for mounting filesystems in user
> namespaces using fuse. They are based on the patches in the for-testing
> branch of
> but I've rebased them onto 4.4-rc3. I've pushed all of this to:
> git://git.kernel.org/pub/scm/linux/kernel/git/sforshee/linux.git fuse-userns
> The patches are organized into three high-level groups.
> Patches 1-6 are related to security, adding restrictions for
> unprivileged mounts and updating the LSMs as needed. Patches 1-2
> (checking inode permissions for block device mounts) may not be strictly
> necessary for fuseblk mounts since fuse doesn't do any IO on the block
> device in the kernel, but it still seems like a good idea to fail the
> mount if the user doesn't have the required permissions for the inode
> (though this is a bit misleading with fuse since the mounts are done via
> a suid-root helper).
> Patches 7-14 update most of the vfs to translate ids correctly and deal
> with inodes which may have invalid user/group ids. I've omitted patches
> for anything not used by fuse - quota, fs freezing, some helper
> functions, etc. - but if these are wanted for the sake of completeness I
> can include them.
> Patches 15-18 update fuse to deal with mounts from non-init pid and user
> namespaces and enable mounting from user namespaces.
> Changes since v1:
> - Drop patch for FIBMAP.
> - Use current_in_userns in fuse_allow_current_process.
> - Remove checks for uid/gid validity in fuse. Intead, ids from the
> backing store which do not map into s_user_ns will result in invalid
> ids in the vfs inode. Checks in the vfs will prevent unmappable ids
> from being passed in from above.
> - Update a couple of commit messages to provide more detail about
Now that the merge window is over, I'm wondering whether it might be
possible to get some feedback on these patches this cycle?