From: Serge Hallyn <serge@hallyn.com>
To: linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org
Cc: dhowells@redhat.com, ebiederm@xmission.com,
"Serge E. Hallyn" <serge.hallyn@canonical.com>
Subject: [RFC PATCH 04/14] user_ns: convert fs/attr.c to targeted capabilities
Date: Tue, 12 Jul 2011 23:30:42 +0000 [thread overview]
Message-ID: <1310513452-13397-5-git-send-email-serge@hallyn.com> (raw)
In-Reply-To: <1310513452-13397-1-git-send-email-serge@hallyn.com>
From: Serge E. Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
---
fs/attr.c | 20 +++++++++++++-------
1 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/fs/attr.c b/fs/attr.c
index caf2aa5..c6d502d 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -29,6 +29,7 @@
int inode_change_ok(const struct inode *inode, struct iattr *attr)
{
unsigned int ia_valid = attr->ia_valid;
+ struct user_namespace *ns;
/*
* First check size constraints. These can't be overriden using
@@ -44,26 +45,28 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr)
if (ia_valid & ATTR_FORCE)
return 0;
+ ns = inode_userns(inode);
/* Make sure a caller can chown. */
if ((ia_valid & ATTR_UID) &&
- (current_fsuid() != inode->i_uid ||
- attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN))
+ (ns != current_user_ns() || current_fsuid() != inode->i_uid ||
+ attr->ia_uid != inode->i_uid) && !ns_capable(ns, CAP_CHOWN))
return -EPERM;
/* Make sure caller can chgrp. */
if ((ia_valid & ATTR_GID) &&
- (current_fsuid() != inode->i_uid ||
+ (ns != current_user_ns() || current_fsuid() != inode->i_uid ||
(!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
- !capable(CAP_CHOWN))
+ !ns_capable(ns, CAP_CHOWN))
return -EPERM;
/* Make sure a caller can chmod. */
if (ia_valid & ATTR_MODE) {
+ gid_t gid = (ia_valid & ATTR_GID) ? attr->ia_gid : inode->i_gid;
if (!inode_owner_or_capable(inode))
return -EPERM;
/* Also check the setgid bit! */
- if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
- inode->i_gid) && !capable(CAP_FSETID))
+ if ((ns != current_user_ns() || !in_group_p(gid)) &&
+ !ns_capable(ns, CAP_FSETID))
attr->ia_mode &= ~S_ISGID;
}
@@ -154,9 +157,12 @@ void setattr_copy(struct inode *inode, const struct iattr *attr)
inode->i_sb->s_time_gran);
if (ia_valid & ATTR_MODE) {
umode_t mode = attr->ia_mode;
+ struct user_namespace *ns = inode_userns(inode);
- if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
+ if ((ns != current_user_ns() || !in_group_p(inode->i_gid)) &&
+ !ns_capable(ns, CAP_FSETID))
mode &= ~S_ISGID;
+
inode->i_mode = mode;
}
}
--
1.7.4.1
next prev parent reply other threads:[~2011-07-12 23:38 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-12 23:30 [RFC PATCH 0/14] user namespaces: continue targetting capabilities Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 01/14] add Documentation/namespaces/user_namespace.txt Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 02/14] allow root in container to copy namespaces Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 03/14] keyctl: check capabilities against key's user_ns Serge Hallyn
2011-07-12 23:30 ` Serge Hallyn [this message]
2011-07-12 23:30 ` [RFC PATCH 05/14] userns: clamp down users of cap_raised Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 06/14] user namespace: make each net (net_ns) belong to a user_ns Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 07/14] user namespace: use net->user_ns for some capable calls under net/ Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 08/14] af_netlink.c: make netlink_capable userns-aware Serge Hallyn
2011-07-13 1:33 ` Eric Dumazet
2011-07-13 2:02 ` Serge E. Hallyn
2011-07-12 23:30 ` [RFC PATCH 09/14] user ns: convert ipv6 to targeted capabilities Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 10/14] net/core/scm.c: target capable() calls to user_ns owning the net_ns Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 11/14] userns: make some net-sysfs capable calls targeted Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 12/14] user_ns: target af_key capability check Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 13/14] userns: net: make many network capable calls targeted Serge Hallyn
2011-07-12 23:30 ` [RFC PATCH 14/14] net: pass user_ns to cap_netlink_recv() Serge Hallyn
2011-07-13 12:45 ` [RFC PATCH 01/14] add Documentation/namespaces/user_namespace.txt David Howells
2011-07-14 2:37 ` Serge E. Hallyn
2011-07-13 16:04 ` [RFC PATCH 03/14] keyctl: check capabilities against key's user_ns David Howells
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1310513452-13397-5-git-send-email-serge@hallyn.com \
--to=serge@hallyn.com \
--cc=containers@lists.linux-foundation.org \
--cc=dhowells@redhat.com \
--cc=ebiederm@xmission.com \
--cc=linux-kernel@vger.kernel.org \
--cc=serge.hallyn@canonical.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®