Re: Regression for MS_MOVE on kernel v5.1

2019-06-14 Thread Eric W. Biederman
Christian Brauner writes: > On Thu, Jun 13, 2019 at 04:59:24PM -0500, Eric W. Biederman wrote: >> Miklos Szeredi writes: >> >> > On Thu, Jun 13, 2019 at 8:35 PM Eric W. Biederman >> > wrote: >> >> >> >> Christian Brauner writes: >> >> >> >> > On Wed, Jun 12, 2019 at 06:00:39PM -1000, Linus T

Re: Regression for MS_MOVE on kernel v5.1

2019-06-13 Thread Christian Brauner
On Thu, Jun 13, 2019 at 04:59:24PM -0500, Eric W. Biederman wrote: > Miklos Szeredi writes: > > > On Thu, Jun 13, 2019 at 8:35 PM Eric W. Biederman > > wrote: > >> > >> Christian Brauner writes: > >> > >> > On Wed, Jun 12, 2019 at 06:00:39PM -1000, Linus Torvalds wrote: > >> >> On Wed, Jun 12,

Re: Regression for MS_MOVE on kernel v5.1

2019-06-13 Thread Eric W. Biederman
Miklos Szeredi writes: > On Thu, Jun 13, 2019 at 8:35 PM Eric W. Biederman > wrote: >> >> Christian Brauner writes: >> >> > On Wed, Jun 12, 2019 at 06:00:39PM -1000, Linus Torvalds wrote: >> >> On Wed, Jun 12, 2019 at 12:54 PM Christian Brauner >> >> wrote: >> >> > >> >> > The commit changes

Re: Regression for MS_MOVE on kernel v5.1

2019-06-13 Thread Miklos Szeredi
On Thu, Jun 13, 2019 at 8:35 PM Eric W. Biederman wrote: > > Christian Brauner writes: > > > On Wed, Jun 12, 2019 at 06:00:39PM -1000, Linus Torvalds wrote: > >> On Wed, Jun 12, 2019 at 12:54 PM Christian Brauner > >> wrote: > >> > > >> > The commit changes the internal logic to lock mounts whe

Re: Regression for MS_MOVE on kernel v5.1

2019-06-13 Thread Eric W. Biederman
Christian Brauner writes: > On Wed, Jun 12, 2019 at 06:00:39PM -1000, Linus Torvalds wrote: >> On Wed, Jun 12, 2019 at 12:54 PM Christian Brauner >> wrote: >> > >> > The commit changes the internal logic to lock mounts when propagating >> > mounts (user+)mount namespaces and - I believe - cause

Regression for MS_MOVE on kernel v5.1

2019-06-13 Thread Christian Brauner
Hey, Sorry to be the bearer of bad news but I think I observed a pretty gnarly regression for userspace with MS_MOVE from kernel v5.1 onwards. When propagating mounts across mount namespaces owned by different user namespaces it is not possible anymore to move the mount in the less privileged mou

Re: Regression for MS_MOVE on kernel v5.1

2019-06-13 Thread Linus Torvalds
On Wed, Jun 12, 2019 at 12:54 PM Christian Brauner wrote: > > The commit changes the internal logic to lock mounts when propagating > mounts (user+)mount namespaces and - I believe - causes do_mount_move() > to fail at: You mean 'do_move_mount()'. > if (old->mnt.mnt_flags & MNT_LOCKED) >

Re: Regression for MS_MOVE on kernel v5.1

2019-06-13 Thread David Howells
[Adding Eric to the cc list since he implemented MNT_LOCKED] Linus Torvalds wrote: > > The commit changes the internal logic to lock mounts when propagating > > mounts (user+)mount namespaces and - I believe - causes do_mount_move() > > to fail at: > > You mean 'do_move_mount()'. > > > if (old

Re: Regression for MS_MOVE on kernel v5.1

2019-06-13 Thread Christian Brauner
On Wed, Jun 12, 2019 at 06:00:39PM -1000, Linus Torvalds wrote: > On Wed, Jun 12, 2019 at 12:54 PM Christian Brauner > wrote: > > > > The commit changes the internal logic to lock mounts when propagating > > mounts (user+)mount namespaces and - I believe - causes do_mount_move() > > to fail at: >