2007-12-12 21:01:25

by Serge E. Hallyn

Subject: [RFC] [PATCH -mm] reiser4: replace uid==0 check with capability

>From c257cb67ce00c8769730cfa92379a53009d99b28 Mon Sep 17 00:00:00 2001
From: [email protected] <[email protected]>
Date: Wed, 5 Dec 2007 14:02:45 -0800
Subject: [RFC] [PATCH -mm] reiser4: replace uid==0 check with capability

Reiser4 gives root some reserved blocks. Replace the uid==0 check, which
is not safe in the face of user namespaces, with a CAP_SYS_RESOURCE check,
which seems appropriate.

The per-uid and per-guid reservations appear unimplemented so I'm ignoring
them.

Signed-off-by: Serge Hallyn <[email protected]>
---
fs/reiser4/super.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/reiser4/super.c b/fs/reiser4/super.c
index bc4113e..50e3d09 100644
--- a/fs/reiser4/super.c
+++ b/fs/reiser4/super.c
@@ -144,7 +144,7 @@ long reiser4_reserved_blocks(const struct super_block *super /* super block
reserved += reserved_for_gid(super, gid);
if (REISER4_SUPPORT_UID_SPACE_RESERVATION)
reserved += reserved_for_uid(super, uid);
- if (REISER4_SUPPORT_ROOT_SPACE_RESERVATION && (uid == 0))
+ if (REISER4_SUPPORT_ROOT_SPACE_RESERVATION && capable(CAP_SYS_RESOURCE))
reserved += reserved_for_root(super);
return reserved;
}
--
1.5.1

2007-12-13 00:36:54

by Edward Shishkin

Subject: Re: [RFC] [PATCH -mm] reiser4: replace uid==0 check with capability

Serge E. Hallyn wrote:

>>From c257cb67ce00c8769730cfa92379a53009d99b28 Mon Sep 17 00:00:00 2001
>From: [email protected] <[email protected]>
>Date: Wed, 5 Dec 2007 14:02:45 -0800
>Subject: [RFC] [PATCH -mm] reiser4: replace uid==0 check with capability
>
>Reiser4 gives root some reserved blocks. Replace the uid==0 check, which
>is not safe in the face of user namespaces, with a CAP_SYS_RESOURCE check,
>which seems appropriate.
>
>
>

Agreed. Thanks,
Edward.

>The per-uid and per-guid reservations appear unimplemented so I'm ignoring
>them.
>
>Signed-off-by: Serge Hallyn <[email protected]>
>---
> fs/reiser4/super.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
>diff --git a/fs/reiser4/super.c b/fs/reiser4/super.c
>index bc4113e..50e3d09 100644
>--- a/fs/reiser4/super.c
>+++ b/fs/reiser4/super.c
>@@ -144,7 +144,7 @@ long reiser4_reserved_blocks(const struct super_block *super /* super block
> reserved += reserved_for_gid(super, gid);
> if (REISER4_SUPPORT_UID_SPACE_RESERVATION)
> reserved += reserved_for_uid(super, uid);
>- if (REISER4_SUPPORT_ROOT_SPACE_RESERVATION && (uid == 0))
>+ if (REISER4_SUPPORT_ROOT_SPACE_RESERVATION && capable(CAP_SYS_RESOURCE))
> reserved += reserved_for_root(super);
> return reserved;
> }
>
>