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Groups > linux.kernel > #1443667
| From | Andrey Vagin <avagin@openvz.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 2/5] kernel: add a helper to get an owning user namespace for a namespace |
| Date | 2016-07-14 20:30 +0200 |
| Message-ID | <rUTyy-4Je-41@gated-at.bofh.it> (permalink) |
| References | <rUTyx-4Je-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Return -EPERM if an owning user namespace is outside of a process
current user namespace.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
---
include/linux/user_namespace.h | 7 +++++++
kernel/user_namespace.c | 24 ++++++++++++++++++++++++
2 files changed, 31 insertions(+)
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index a941b44..e416b76 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -76,6 +76,8 @@ extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t,
extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
extern int proc_setgroups_show(struct seq_file *m, void *v);
extern bool userns_may_setgroups(const struct user_namespace *ns);
+
+struct ns_common *ns_get_owner(struct ns_common *ns);
#else
static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
@@ -104,6 +106,11 @@ static inline bool userns_may_setgroups(const struct user_namespace *ns)
{
return true;
}
+
+static inline struct ns_common *ns_get_owner(struct ns_common *ns)
+{
+ return ERR_PTR(-ENOENT);
+}
#endif
#endif /* _LINUX_USER_H */
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index a5bc78c..6382e5e 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -994,6 +994,30 @@ static int userns_install(struct nsproxy *nsproxy, struct ns_common *ns)
return commit_creds(cred);
}
+struct ns_common *ns_get_owner(struct ns_common *ns)
+{
+ const struct cred *cred = current_cred();
+ struct user_namespace *user_ns, *p;
+
+ user_ns = p = ns->user_ns;
+ if (user_ns == NULL) { /* ns is init_user_ns */
+ /* Unprivileged user should not know that it's init_user_ns. */
+ if (capable(CAP_SYS_ADMIN))
+ return ERR_PTR(-ENOENT);
+ return ERR_PTR(-EPERM);
+ }
+
+ for (;;) {
+ if (p == cred->user_ns)
+ break;
+ if (p == &init_user_ns)
+ return ERR_PTR(-EPERM);
+ p = p->parent;
+ }
+
+ return &get_user_ns(user_ns)->ns;
+}
+
const struct proc_ns_operations userns_operations = {
.name = "user",
.type = CLONE_NEWUSER,
--
2.5.5
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[PATCH 0/5 RFC] Add an interface to discover relationships between namespaces Andrey Vagin <avagin@openvz.org> - 2016-07-14 20:30 +0200
[PATCH 2/5] kernel: add a helper to get an owning user namespace for a namespace Andrey Vagin <avagin@openvz.org> - 2016-07-14 20:30 +0200
Re: [PATCH 2/5] kernel: add a helper to get an owning user namespace for a namespace "W. Trevor King" <wking@tremily.us> - 2016-07-14 21:10 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces Andrey Vagin <avagin@openvz.org> - 2016-07-15 00:10 +0200
[PATCH 5/5] tools/testing: add a test to check nsfs ioctl-s Andrey Vagin <avagin@openvz.org> - 2016-07-15 04:20 +0200
[PATCH 4/5] nsfs: add ioctl to get a parent namespace Andrey Vagin <avagin@openvz.org> - 2016-07-15 04:20 +0200
Re: [PATCH 4/5] nsfs: add ioctl to get a parent namespace ebiederm@xmission.com (Eric W. Biederman) - 2016-07-24 07:30 +0200
[PATCH 3/5] nsfs: add ioctl to get an owning user namespace for ns file descriptor Andrey Vagin <avagin@openvz.org> - 2016-07-15 04:20 +0200
[PATCH 2/5] kernel: add a helper to get an owning user namespace for a namespace Andrey Vagin <avagin@openvz.org> - 2016-07-15 04:20 +0200
Re: [PATCH 2/5] kernel: add a helper to get an owning user namespace for a namespace ebiederm@xmission.com (Eric W. Biederman) - 2016-07-24 07:20 +0200
Re: [PATCH 2/5] kernel: add a helper to get an owning user namespace for a namespace ebiederm@xmission.com (Eric W. Biederman) - 2016-07-24 16:50 +0200
Re: [PATCH 2/5] kernel: add a helper to get an owning user namespace for a namespace "W. Trevor King" <wking@tremily.us> - 2016-07-24 19:10 +0200
Re: [PATCH 2/5] kernel: add a helper to get an owning user namespace for a namespace "W. Trevor King" <wking@tremily.us> - 2016-07-24 19:00 +0200
Re: [PATCH 1/5] namespaces: move user_ns into ns_common ebiederm@xmission.com (Eric W. Biederman) - 2016-07-24 07:20 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces ebiederm@xmission.com (Eric W. Biederman) - 2016-07-24 07:30 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> - 2016-07-21 16:50 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces Andrey Vagin <avagin@openvz.org> - 2016-07-22 20:30 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> - 2016-07-25 13:50 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces ebiederm@xmission.com (Eric W. Biederman) - 2016-07-25 15:40 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> - 2016-07-25 16:50 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2016-07-25 17:00 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces ebiederm@xmission.com (Eric W. Biederman) - 2016-07-25 17:40 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces ebiederm@xmission.com (Eric W. Biederman) - 2016-07-25 17:20 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces "W. Trevor King" <wking@tremily.us> - 2016-07-23 23:20 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces James Bottomley <James.Bottomley@HansenPartnership.com> - 2016-07-23 23:40 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces "W. Trevor King" <wking@tremily.us> - 2016-07-24 00:10 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces ebiederm@xmission.com (Eric W. Biederman) - 2016-07-24 00:20 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces "W. Trevor King" <wking@tremily.us> - 2016-07-24 00:40 +0200
Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces ebiederm@xmission.com (Eric W. Biederman) - 2016-07-24 07:10 +0200
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