Re: [PATCH RFC v11 11/19] dm verity: set DM_TARGET_SINGLETON feature flag

Paul Moore
2023-11-02T00:41:05Z

On Mon, Oct 23, 2023 at 11:52 PM Paul Moore <paul@paul-moore.com> wrote:
> On Oct 4, 2023 Fan Wu <wufan@linux.microsoft.com> wrote:
> >
> > The device-mapper has a flag to mark targets as singleton, which is a
> > required flag for immutable targets. Without this flag, multiple
> > dm-verity targets can be added to a mapped device, which has no
> > practical use cases and will let dm_table_get_immutable_target return
> > NULL. This patch adds the missing flag, restricting only one
> > dm-verity target per mapped device.
> >
> > Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
> > ---
> > v1-v10:
> > + Not present
> > ---
> > drivers/md/dm-verity-target.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
>
> This seems reasonable to me and matches with other users of
> DM_TARGET_IMMUTABLE.
>
> Alasdair, Mike, can we get an ACK on this?

A gentle ping with a reminder ...

For reference, the full patchset can be found on lore at the link below:

https://lore.kernel.org/linux-security-module/1696457386-3010-1-git-send-email-wufan@linux.microsoft.com/

> > diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
> > index 26adcfea0302..80673b66c194 100644
> > --- a/drivers/md/dm-verity-target.c
> > +++ b/drivers/md/dm-verity-target.c
> > @@ -1503,7 +1503,7 @@ int dm_verity_get_root_digest(struct dm_target *ti, u8 **root_digest, unsigned i
> >
> > static struct target_type verity_target = {
> > .name = "verity",
> > - .features = DM_TARGET_IMMUTABLE,
> > + .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE,
> > .version = {1, 9, 0},
> > .module = THIS_MODULE,
> > .ctr = verity_ctr,
> > --
> > 2.25.1

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