Re: [PATCH 1/2] ecryptfs: fix uid translation for setxattr on security.capability

From: Miklos Szeredi
Date: Wed Jan 20 2021 - 02:55:01 EST


On Tue, Jan 19, 2021 at 10:11 PM Eric W. Biederman
<ebiederm@xxxxxxxxxxxx> wrote:
>
> Miklos Szeredi <mszeredi@xxxxxxxxxx> writes:
>
> > Prior to commit 7c03e2cda4a5 ("vfs: move cap_convert_nscap() call into
> > vfs_setxattr()") the translation of nscap->rootid did not take stacked
> > filesystems (overlayfs and ecryptfs) into account.
> >
> > That patch fixed the overlay case, but made the ecryptfs case worse.
> >
> > Restore old the behavior for ecryptfs that existed before the overlayfs
> > fix. This does not fix ecryptfs's handling of complex user namespace
> > setups, but it does make sure existing setups don't regress.
>
> Today vfs_setxattr handles handles a delegated_inode and breaking
> leases. Code that is enabled with CONFIG_FILE_LOCKING. So unless
> I am missing something this introduces a different regression into
> ecryptfs.

This is in line with all the other cases of ecryptfs passing NULL as
delegated inode.

I'll defer this to the maintainer of ecryptfs.

Thanks,
Miklos