[PATCH] Reallow AUTH_NULL on v4 mounts.

[PATCH] Reallow AUTH_NULL on v4 mounts.

[J. Bruce Fields]

From: "J. Bruce Fields" <bfields@redhat.com>

Kinglong Mee noted that the loop in seicnfo_addflavor (which sets the
security flavors allowed on the v4 pseudoroot) was adding flavors 1 and
0 twice; this is because flav_map ends with these entries:

	{ "unix",       AUTH_UNIX               },
        { "sys",        AUTH_SYS                },
        { "null",       AUTH_NULL               },
        { "none",       AUTH_NONE               },

where AUTH_UNIX == AUTH_SYS == 1 and AUTH_NULL == AUTH_NONE == 1.  We
need to allow two names for each of those two security flavors for
historical reasons.

The patch correctly fixed this by fixing the check for a duplicate
flavor number in secinfo_addflavor().  However it also went one step
further and rejected the flavor number 0.  This is unnecessary and
causes the kernel to fail any NFSv4 mounts using AUTH_NULL.

The fact that we've apparently gone a few years without anyone noticing
this suggests AUTH_NULL isn't used very much!  Still, this should be
fixed....

Fixes: e69eaaf93626
Cc: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 utils/mountd/v4root.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/utils/mountd/v4root.c b/utils/mountd/v4root.c
index d735dbfe192d..c93bd4db51c8 100644
--- a/utils/mountd/v4root.c
+++ b/utils/mountd/v4root.c
@@ -69,9 +69,6 @@ set_pseudofs_security(struct exportent *pseudo, int flags)
 	for (flav = flav_map; flav < flav_map + flav_map_size; flav++) {
 		struct sec_entry *new;
 
-		if (!flav->fnum)
-			continue;
-
 		i = secinfo_addflavor(flav, pseudo);
 		new = &pseudo->e_secinfo[i];
 
-- 
2.17.1

Re: [PATCH] Reallow AUTH_NULL on v4 mounts.

[Chuck Lever]

> On Jun 14, 2018, at 9:52 AM, bfields@fieldses.org wrote:
>=20
> From: "J. Bruce Fields" <bfields@redhat.com>
>=20
> Kinglong Mee noted that the loop in seicnfo_addflavor (which sets the
> security flavors allowed on the v4 pseudoroot) was adding flavors 1 =
and
> 0 twice; this is because flav_map ends with these entries:
>=20
> 	{ "unix",       AUTH_UNIX               },
>        { "sys",        AUTH_SYS                },
>        { "null",       AUTH_NULL               },
>        { "none",       AUTH_NONE               },
>=20
> where AUTH_UNIX =3D=3D AUTH_SYS =3D=3D 1 and AUTH_NULL =3D=3D =
AUTH_NONE =3D=3D 1.

Hi Bruce, patch description may be incorrect: NULL and NONE should be 0.

> We
> need to allow two names for each of those two security flavors for
> historical reasons.
>=20
> The patch correctly fixed this by fixing the check for a duplicate
> flavor number in secinfo_addflavor().  However it also went one step
> further and rejected the flavor number 0.  This is unnecessary and
> causes the kernel to fail any NFSv4 mounts using AUTH_NULL.
>=20
> The fact that we've apparently gone a few years without anyone =
noticing
> this suggests AUTH_NULL isn't used very much!  Still, this should be
> fixed....
>=20
> Fixes: e69eaaf93626
> Cc: Kinglong Mee <kinglongmee@gmail.com>
> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> ---
> utils/mountd/v4root.c | 3 ---
> 1 file changed, 3 deletions(-)
>=20
> diff --git a/utils/mountd/v4root.c b/utils/mountd/v4root.c
> index d735dbfe192d..c93bd4db51c8 100644
> --- a/utils/mountd/v4root.c
> +++ b/utils/mountd/v4root.c
> @@ -69,9 +69,6 @@ set_pseudofs_security(struct exportent *pseudo, int =
flags)
> 	for (flav =3D flav_map; flav < flav_map + flav_map_size; flav++) =
{
> 		struct sec_entry *new;
>=20
> -		if (!flav->fnum)
> -			continue;
> -
> 		i =3D secinfo_addflavor(flav, pseudo);
> 		new =3D &pseudo->e_secinfo[i];
>=20
> --=20
> 2.17.1
>=20
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" =
in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
Chuck Lever

Re: [PATCH] Reallow AUTH_NULL on v4 mounts.

[Bruce Fields]

On Thu, Jun 14, 2018 at 10:21:39AM -0400, Chuck Lever wrote:
> 
> 
> > On Jun 14, 2018, at 9:52 AM, bfields@fieldses.org wrote:
> > 
> > From: "J. Bruce Fields" <bfields@redhat.com>
> > 
> > Kinglong Mee noted that the loop in seicnfo_addflavor (which sets the
> > security flavors allowed on the v4 pseudoroot) was adding flavors 1 and
> > 0 twice; this is because flav_map ends with these entries:
> > 
> > 	{ "unix",       AUTH_UNIX               },
> >        { "sys",        AUTH_SYS                },
> >        { "null",       AUTH_NULL               },
> >        { "none",       AUTH_NONE               },
> > 
> > where AUTH_UNIX == AUTH_SYS == 1 and AUTH_NULL == AUTH_NONE == 1.
> 
> Hi Bruce, patch description may be incorrect: NULL and NONE should be 0.

Yes, thanks!  Steve, let me know if you want me to resend or correct the
typo yourself.--b.

> 
> > We
> > need to allow two names for each of those two security flavors for
> > historical reasons.
> > 
> > The patch correctly fixed this by fixing the check for a duplicate
> > flavor number in secinfo_addflavor().  However it also went one step
> > further and rejected the flavor number 0.  This is unnecessary and
> > causes the kernel to fail any NFSv4 mounts using AUTH_NULL.
> > 
> > The fact that we've apparently gone a few years without anyone noticing
> > this suggests AUTH_NULL isn't used very much!  Still, this should be
> > fixed....
> > 
> > Fixes: e69eaaf93626
> > Cc: Kinglong Mee <kinglongmee@gmail.com>
> > Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> > ---
> > utils/mountd/v4root.c | 3 ---
> > 1 file changed, 3 deletions(-)
> > 
> > diff --git a/utils/mountd/v4root.c b/utils/mountd/v4root.c
> > index d735dbfe192d..c93bd4db51c8 100644
> > --- a/utils/mountd/v4root.c
> > +++ b/utils/mountd/v4root.c
> > @@ -69,9 +69,6 @@ set_pseudofs_security(struct exportent *pseudo, int flags)
> > 	for (flav = flav_map; flav < flav_map + flav_map_size; flav++) {
> > 		struct sec_entry *new;
> > 
> > -		if (!flav->fnum)
> > -			continue;
> > -
> > 		i = secinfo_addflavor(flav, pseudo);
> > 		new = &pseudo->e_secinfo[i];
> > 
> > -- 
> > 2.17.1
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> --
> Chuck Lever
> 
>