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 v2 20/28] open: handle fsid mappings
Date: Fri, 14 Feb 2020 19:35:46 +0100 [thread overview]
Message-ID: <20200214183554.1133805-21-christian.brauner@ubuntu.com> (raw)
In-Reply-To: <20200214183554.1133805-1-christian.brauner@ubuntu.com>
Let chown_common() 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.
do_faccessat() just needs to translate from real ids into fsids.
Filesystems that share a superblock in all user namespaces they are mounted in
will retain their old semantics even with the introduction of fsidmappings.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
/* v2 */
- Christian Brauner <christian.brauner@ubuntu.com>:
- handle faccessat() too
---
fs/open.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/fs/open.c b/fs/open.c
index 0788b3715731..4e092845728f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -32,6 +32,7 @@
#include <linux/ima.h>
#include <linux/dnotify.h>
#include <linux/compat.h>
+#include <linux/fsuidgid.h>
#include "internal.h"
@@ -361,8 +362,10 @@ long do_faccessat(int dfd, const char __user *filename, int mode)
if (!override_cred)
return -ENOMEM;
- override_cred->fsuid = override_cred->uid;
- override_cred->fsgid = override_cred->gid;
+ override_cred->kfsuid = override_cred->uid;
+ override_cred->kfsgid = override_cred->gid;
+ override_cred->fsuid = kuid_to_kfsuid(override_cred->user_ns, override_cred->uid);
+ override_cred->fsgid = kgid_to_kfsgid(override_cred->user_ns, override_cred->gid);
if (!issecure(SECURE_NO_SETUID_FIXUP)) {
/* Clear the capabilities if we switch to a non-root user */
@@ -626,8 +629,13 @@ static int chown_common(const struct path *path, uid_t user, gid_t group)
kuid_t uid;
kgid_t gid;
- uid = make_kuid(current_user_ns(), user);
- gid = make_kgid(current_user_ns(), group);
+ if (is_userns_visible(inode->i_sb->s_iflags)) {
+ uid = make_kuid(current_user_ns(), user);
+ gid = make_kgid(current_user_ns(), group);
+ } else {
+ uid = make_kfsuid(current_user_ns(), user);
+ gid = make_kfsgid(current_user_ns(), group);
+ }
retry_deleg:
newattrs.ia_valid = ATTR_CTIME;
--
2.25.0
next prev parent reply other threads:[~2020-02-14 18:41 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-14 18:35 [PATCH v2 00/28] user_namespace: introduce fsid mappings Christian Brauner
2020-02-14 18:35 ` [PATCH v2 01/28] user_namespace: introduce fsid mappings infrastructure Christian Brauner
2020-02-14 18:35 ` [PATCH v2 02/28] proc: add /proc/<pid>/fsuid_map Christian Brauner
2020-02-14 18:35 ` [PATCH v2 03/28] proc: add /proc/<pid>/fsgid_map Christian Brauner
2020-02-14 18:35 ` [PATCH v2 04/28] fsuidgid: add fsid mapping helpers Christian Brauner
2020-02-14 19:11 ` Jann Horn
2020-02-16 16:55 ` Christian Brauner
2020-02-14 18:35 ` [PATCH v2 05/28] proc: task_state(): use from_kfs{g,u}id_munged Christian Brauner
2020-02-14 18:35 ` [PATCH v2 06/28] cred: add kfs{g,u}id Christian Brauner
2020-02-14 18:35 ` [PATCH v2 07/28] sys: __sys_setfsuid(): handle fsid mappings Christian Brauner
2020-02-14 18:35 ` [PATCH v2 08/28] sys: __sys_setfsgid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 09/28] sys:__sys_setuid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 10/28] sys:__sys_setgid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 11/28] sys:__sys_setreuid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 12/28] sys:__sys_setregid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 13/28] sys:__sys_setresuid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 14/28] sys:__sys_setresgid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 15/28] fs: add is_userns_visible() helper Christian Brauner
2020-02-14 18:35 ` [PATCH v2 16/28] namei: may_{o_}create(): handle fsid mappings Christian Brauner
2020-02-14 18:35 ` [PATCH v2 17/28] inode: inode_owner_or_capable(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 18/28] capability: privileged_wrt_inode_uidgid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 19/28] stat: " Christian Brauner
2020-02-14 19:03 ` Tycho Andersen
2020-02-16 14:12 ` Christian Brauner
2020-02-14 18:35 ` Christian Brauner [this message]
2020-02-14 18:35 ` [PATCH v2 21/28] posix_acl: " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 22/28] attr: notify_change(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 23/28] commoncap: cap_bprm_set_creds(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 24/28] commoncap: cap_task_fix_setuid(): " Christian Brauner
2020-02-14 18:35 ` [PATCH v2 25/28] commoncap: handle fsid mappings with vfs caps Christian Brauner
2020-02-14 18:35 ` [PATCH v2 26/28] exec: bprm_fill_uid(): handle fsid mappings Christian Brauner
2020-02-14 18:35 ` [PATCH v2 27/28] ptrace: adapt ptrace_may_access() to always uses unmapped fsids Christian Brauner
2020-02-14 18:35 ` [PATCH v2 28/28] devpts: handle fsid mappings Christian Brauner
2020-02-16 15:55 ` [PATCH v2 00/28] user_namespace: introduce " Florian Weimer
2020-02-16 16:40 ` Christian Brauner
2020-02-17 21:06 ` James Bottomley
2020-02-17 21:20 ` Christian Brauner
2020-02-17 22:35 ` James Bottomley
2020-02-17 23:05 ` Christian Brauner
2020-02-17 21:11 ` James Bottomley
[not found] ` <CA+enf=vwd-dxzve87t7Mw1Z35RZqdLzVaKq=fZ4EGOpnES0f5w@mail.gmail.com>
2020-02-17 22:02 ` Stéphane Graber
2020-02-17 23:03 ` James Bottomley
2020-02-17 23:11 ` Stéphane Graber
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