From: Christian Brauner <christian.brauner@ubuntu.com>
To: "Stéphane Graber" <stgraber@ubuntu.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"Aleksa Sarai" <cyphar@cyphar.com>,
"Jann Horn" <jannh@google.com>
Cc: smbarber@chromium.org, Seth Forshee <seth.forshee@canonical.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Alexey Dobriyan <adobriyan@gmail.com>,
Serge Hallyn <serge@hallyn.com>, James Morris <jmorris@namei.org>,
Kees Cook <keescook@chromium.org>,
Jonathan Corbet <corbet@lwn.net>, Phil Estes <estesp@gmail.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
containers@lists.linux-foundation.org,
linux-security-module@vger.kernel.org, linux-api@vger.kernel.org,
Christian Brauner <christian.brauner@ubuntu.com>
Subject: [PATCH v3 16/25] attr: notify_change(): handle fsid mappings
Date: Tue, 18 Feb 2020 15:34:02 +0100 [thread overview]
Message-ID: <20200218143411.2389182-17-christian.brauner@ubuntu.com> (raw)
In-Reply-To: <20200218143411.2389182-1-christian.brauner@ubuntu.com>
Switch notify_change() to lookup fsids in the fsid mappings. If no fsid
mappings are setup the behavior is unchanged, i.e. fsids are looked up in the
id mappings.
Filesystems that share a superblock in all user namespaces they are mounted in
will retain their old semantics even with the introduction of fsid mappings.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
/* v2 */
unchanged
/* v3 */
unchanged
---
fs/attr.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/fs/attr.c b/fs/attr.c
index b4bbdbd4c8ca..b3fe9d9582d2 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -17,6 +17,8 @@
#include <linux/security.h>
#include <linux/evm.h>
#include <linux/ima.h>
+#include <linux/fsuidgid.h>
+#include <linux/fs.h>
static bool chown_ok(const struct inode *inode, kuid_t uid)
{
@@ -310,12 +312,21 @@ int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **de
* Verify that uid/gid changes are valid in the target
* namespace of the superblock.
*/
- if (ia_valid & ATTR_UID &&
- !kuid_has_mapping(inode->i_sb->s_user_ns, attr->ia_uid))
- return -EOVERFLOW;
- if (ia_valid & ATTR_GID &&
- !kgid_has_mapping(inode->i_sb->s_user_ns, attr->ia_gid))
- return -EOVERFLOW;
+ if (is_userns_visible(inode->i_sb->s_iflags)) {
+ if (ia_valid & ATTR_UID &&
+ !kuid_has_mapping(inode->i_sb->s_user_ns, attr->ia_uid))
+ return -EOVERFLOW;
+ if (ia_valid & ATTR_GID &&
+ !kgid_has_mapping(inode->i_sb->s_user_ns, attr->ia_gid))
+ return -EOVERFLOW;
+ } else {
+ if (ia_valid & ATTR_UID &&
+ !kfsuid_has_mapping(inode->i_sb->s_user_ns, attr->ia_uid))
+ return -EOVERFLOW;
+ if (ia_valid & ATTR_GID &&
+ !kfsgid_has_mapping(inode->i_sb->s_user_ns, attr->ia_gid))
+ return -EOVERFLOW;
+ }
/* Don't allow modifications of files with invalid uids or
* gids unless those uids & gids are being made valid.
--
2.25.0
next prev parent reply other threads:[~2020-02-18 14:35 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 14:33 [PATCH v3 00/25] user_namespace: introduce fsid mappings Christian Brauner
2020-02-18 14:33 ` [PATCH v3 01/25] user_namespace: introduce fsid mappings infrastructure Christian Brauner
2020-02-19 2:33 ` Serge E. Hallyn
2020-02-18 14:33 ` [PATCH v3 02/25] proc: add /proc/<pid>/fsuid_map Christian Brauner
2020-02-19 2:33 ` Serge E. Hallyn
2020-02-18 14:33 ` [PATCH v3 03/25] proc: add /proc/<pid>/fsgid_map Christian Brauner
2020-02-19 2:33 ` Serge E. Hallyn
2020-02-18 14:33 ` [PATCH v3 04/25] fsuidgid: add fsid mapping helpers Christian Brauner
2020-02-18 14:33 ` [PATCH v3 05/25] user_namespace: refactor map_write() Christian Brauner
2020-02-19 2:35 ` Serge E. Hallyn
2020-02-18 14:33 ` [PATCH v3 06/25] user_namespace: make map_write() support fsid mappings Christian Brauner
2020-02-19 16:18 ` Jann Horn
2020-02-18 14:33 ` [PATCH v3 07/25] proc: task_state(): use from_kfs{g,u}id_munged Christian Brauner
2020-02-19 2:36 ` Serge E. Hallyn
2020-02-18 14:33 ` [PATCH v3 08/25] cred: add kfs{g,u}id Christian Brauner
2020-02-18 14:33 ` [PATCH v3 09/25] fs: add is_userns_visible() helper Christian Brauner
2020-02-19 2:42 ` Serge E. Hallyn
2020-02-19 12:06 ` Christian Brauner
2020-02-19 17:18 ` Andy Lutomirski
2020-02-20 14:26 ` Serge E. Hallyn
2020-02-18 14:33 ` [PATCH v3 10/25] namei: may_{o_}create(): handle fsid mappings Christian Brauner
2020-02-18 14:33 ` [PATCH v3 11/25] inode: inode_owner_or_capable(): " Christian Brauner
2020-02-18 22:25 ` Christoph Hellwig
2020-02-19 12:29 ` Christian Brauner
2020-02-18 14:33 ` [PATCH v3 12/25] capability: privileged_wrt_inode_uidgid(): " Christian Brauner
2020-02-18 14:33 ` [PATCH v3 13/25] stat: " Christian Brauner
2020-02-18 14:34 ` [PATCH v3 14/25] open: " Christian Brauner
2020-02-18 14:34 ` [PATCH v3 15/25] posix_acl: " Christian Brauner
2020-02-18 22:26 ` Christoph Hellwig
2020-02-19 12:56 ` Christian Brauner
2020-02-18 14:34 ` Christian Brauner [this message]
2020-02-18 14:34 ` [PATCH v3 17/25] commoncap: cap_bprm_set_creds(): " Christian Brauner
2020-02-18 14:34 ` [PATCH v3 18/25] commoncap: cap_task_fix_setuid(): " Christian Brauner
2020-02-18 14:34 ` [PATCH v3 19/25] commoncap: handle fsid mappings with vfs caps Christian Brauner
2020-02-19 15:53 ` Jann Horn
2020-02-18 14:34 ` [PATCH v3 20/25] exec: bprm_fill_uid(): handle fsid mappings Christian Brauner
2020-02-18 14:34 ` [PATCH v3 21/25] ptrace: adapt ptrace_may_access() to always uses unmapped fsids Christian Brauner
2020-02-18 14:34 ` [PATCH v3 22/25] devpts: handle fsid mappings Christian Brauner
2020-02-18 14:34 ` [PATCH v3 23/25] keys: " Christian Brauner
2020-02-18 14:34 ` [PATCH v3 24/25] sys: handle fsid mappings in set*id() calls Christian Brauner
2020-02-19 15:42 ` Jann Horn
2020-02-18 14:34 ` [PATCH v3 25/25] selftests: add simple fsid mapping selftests Christian Brauner
2020-02-18 23:50 ` [PATCH v3 00/25] user_namespace: introduce fsid mappings James Bottomley
2020-02-19 12:27 ` Christian Brauner
2020-02-19 15:36 ` James Bottomley
2020-02-19 15:33 ` Jann Horn
2020-02-19 19:35 ` Serge E. Hallyn
2020-02-19 21:48 ` Serge E. Hallyn
2020-02-19 21:56 ` Tycho Andersen
2020-02-27 19:33 ` Josef Bacik
2020-03-02 14:34 ` Serge E. Hallyn
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