From: "\"Eric W. Beiderman" <ebiederm@xmission.com>
To: <linux-kernel@vger.kernel.org>
Cc: <linux-fsdevel@vger.kernel.org>,
<linux-security-module@vger.kernel.org>,
Linux Containers <containers@lists.linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Al Viro <viro@ZenIV.linux.org.uk>,
Cyrill Gorcunov <gorcunov@openvz.org>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: [PATCH 15/43] userns: Disassociate user_struct from the user_namespace.
Date: Sat, 7 Apr 2012 22:15:11 -0700 [thread overview]
Message-ID: <1333862139-31737-15-git-send-email-ebiederm@xmission.com> (raw)
In-Reply-To: <m11unyn70b.fsf@fess.ebiederm.org>
From: Eric W. Biederman <ebiederm@xmission.com>
Modify alloc_uid to take a kuid and make the user hash table global.
Stop holding a reference to the user namespace in struct user_struct.
This simplifies the code and makes the per user accounting not
care about which user namespace a uid happens to appear in.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
fs/ioprio.c | 18 ++++++++++++++----
include/linux/sched.h | 8 ++++----
include/linux/user_namespace.h | 4 ----
kernel/sys.c | 34 +++++++++++++++++++++++-----------
kernel/user.c | 28 +++++++++++++---------------
kernel/user_namespace.c | 6 +-----
6 files changed, 55 insertions(+), 43 deletions(-)
diff --git a/fs/ioprio.c b/fs/ioprio.c
index 0f1b951..8e35e96 100644
--- a/fs/ioprio.c
+++ b/fs/ioprio.c
@@ -65,6 +65,7 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
struct task_struct *p, *g;
struct user_struct *user;
struct pid *pgrp;
+ kuid_t uid;
int ret;
switch (class) {
@@ -110,16 +111,21 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case IOPRIO_WHO_USER:
+ uid = make_kuid(current_user_ns(), who);
+ if (!uid_valid(uid))
+ break;
if (!who)
user = current_user();
else
- user = find_user(who);
+ user = find_user(uid);
if (!user)
break;
do_each_thread(g, p) {
- if (__task_cred(p)->uid != who)
+ const struct cred *tcred = __task_cred(p);
+ kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid);
+ if (!uid_eq(tcred_uid, uid))
continue;
ret = set_task_ioprio(p, ioprio);
if (ret)
@@ -174,6 +180,7 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
struct task_struct *g, *p;
struct user_struct *user;
struct pid *pgrp;
+ kuid_t uid;
int ret = -ESRCH;
int tmpio;
@@ -203,16 +210,19 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case IOPRIO_WHO_USER:
+ uid = make_kuid(current_user_ns(), who);
if (!who)
user = current_user();
else
- user = find_user(who);
+ user = find_user(uid);
if (!user)
break;
do_each_thread(g, p) {
- if (__task_cred(p)->uid != user->uid)
+ const struct cred *tcred = __task_cred(p);
+ kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid);
+ if (!uid_eq(tcred_uid, user->uid))
continue;
tmpio = get_task_ioprio(p);
if (tmpio < 0)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6867ae9..5fdc1eb 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -90,6 +90,7 @@ struct sched_param {
#include <linux/latencytop.h>
#include <linux/cred.h>
#include <linux/llist.h>
+#include <linux/uidgid.h>
#include <asm/processor.h>
@@ -728,8 +729,7 @@ struct user_struct {
/* Hash table maintenance information */
struct hlist_node uidhash_node;
- uid_t uid;
- struct user_namespace *_user_ns; /* Don't use will be removed soon */
+ kuid_t uid;
#ifdef CONFIG_PERF_EVENTS
atomic_long_t locked_vm;
@@ -738,7 +738,7 @@ struct user_struct {
extern int uids_sysfs_init(void);
-extern struct user_struct *find_user(uid_t);
+extern struct user_struct *find_user(kuid_t);
extern struct user_struct root_user;
#define INIT_USER (&root_user)
@@ -2177,7 +2177,7 @@ extern struct task_struct *find_task_by_pid_ns(pid_t nr,
extern void __set_special_pids(struct pid *pid);
/* per-UID process charging. */
-extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
+extern struct user_struct * alloc_uid(kuid_t);
static inline struct user_struct *get_uid(struct user_struct *u)
{
atomic_inc(&u->__count);
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index dc2d85a..d767508 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -6,12 +6,8 @@
#include <linux/sched.h>
#include <linux/err.h>
-#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7)
-#define UIDHASH_SZ (1 << UIDHASH_BITS)
-
struct user_namespace {
struct kref kref;
- struct hlist_head uidhash_table[UIDHASH_SZ];
struct user_namespace *parent;
struct user_struct *creator;
struct work_struct destroyer;
diff --git a/kernel/sys.c b/kernel/sys.c
index 7185241..f0c43b4 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -175,6 +175,8 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
const struct cred *cred = current_cred();
int error = -EINVAL;
struct pid *pgrp;
+ kuid_t cred_uid;
+ kuid_t uid;
if (which > PRIO_USER || which < PRIO_PROCESS)
goto out;
@@ -207,18 +209,22 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case PRIO_USER:
+ cred_uid = make_kuid(cred->user_ns, cred->uid);
+ uid = make_kuid(cred->user_ns, who);
user = cred->user;
if (!who)
- who = cred->uid;
- else if ((who != cred->uid) &&
- !(user = find_user(who)))
+ uid = cred_uid;
+ else if (!uid_eq(uid, cred_uid) &&
+ !(user = find_user(uid)))
goto out_unlock; /* No processes for this user */
do_each_thread(g, p) {
- if (__task_cred(p)->uid == who)
+ const struct cred *tcred = __task_cred(p);
+ kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid);
+ if (uid_eq(tcred_uid, uid))
error = set_one_prio(p, niceval, error);
} while_each_thread(g, p);
- if (who != cred->uid)
+ if (!uid_eq(uid, cred_uid))
free_uid(user); /* For find_user() */
break;
}
@@ -242,6 +248,8 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
const struct cred *cred = current_cred();
long niceval, retval = -ESRCH;
struct pid *pgrp;
+ kuid_t cred_uid;
+ kuid_t uid;
if (which > PRIO_USER || which < PRIO_PROCESS)
return -EINVAL;
@@ -272,21 +280,25 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case PRIO_USER:
+ cred_uid = make_kuid(cred->user_ns, cred->uid);
+ uid = make_kuid(cred->user_ns, who);
user = cred->user;
if (!who)
- who = cred->uid;
- else if ((who != cred->uid) &&
- !(user = find_user(who)))
+ uid = cred_uid;
+ else if (!uid_eq(uid, cred_uid) &&
+ !(user = find_user(uid)))
goto out_unlock; /* No processes for this user */
do_each_thread(g, p) {
- if (__task_cred(p)->uid == who) {
+ const struct cred *tcred = __task_cred(p);
+ kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid);
+ if (uid_eq(tcred_uid, uid)) {
niceval = 20 - task_nice(p);
if (niceval > retval)
retval = niceval;
}
} while_each_thread(g, p);
- if (who != cred->uid)
+ if (!uid_eq(uid, cred_uid))
free_uid(user); /* for find_user() */
break;
}
@@ -629,7 +641,7 @@ static int set_user(struct cred *new)
{
struct user_struct *new_user;
- new_user = alloc_uid(current_user_ns(), new->uid);
+ new_user = alloc_uid(make_kuid(new->user_ns, new->uid));
if (!new_user)
return -EAGAIN;
diff --git a/kernel/user.c b/kernel/user.c
index d65fec0..025077e 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -34,11 +34,14 @@ EXPORT_SYMBOL_GPL(init_user_ns);
* when changing user ID's (ie setuid() and friends).
*/
+#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7)
+#define UIDHASH_SZ (1 << UIDHASH_BITS)
#define UIDHASH_MASK (UIDHASH_SZ - 1)
#define __uidhashfn(uid) (((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK)
-#define uidhashentry(ns, uid) ((ns)->uidhash_table + __uidhashfn((uid)))
+#define uidhashentry(uid) (uidhash_table + __uidhashfn((__kuid_val(uid))))
static struct kmem_cache *uid_cachep;
+struct hlist_head uidhash_table[UIDHASH_SZ];
/*
* The uidhash_lock is mostly taken from process context, but it is
@@ -58,7 +61,7 @@ struct user_struct root_user = {
.files = ATOMIC_INIT(0),
.sigpending = ATOMIC_INIT(0),
.locked_shm = 0,
- ._user_ns = &init_user_ns,
+ .uid = GLOBAL_ROOT_UID,
};
/*
@@ -72,16 +75,15 @@ static void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent)
static void uid_hash_remove(struct user_struct *up)
{
hlist_del_init(&up->uidhash_node);
- put_user_ns(up->_user_ns); /* It is safe to free the uid hash table now */
}
-static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
+static struct user_struct *uid_hash_find(kuid_t uid, struct hlist_head *hashent)
{
struct user_struct *user;
struct hlist_node *h;
hlist_for_each_entry(user, h, hashent, uidhash_node) {
- if (user->uid == uid) {
+ if (uid_eq(user->uid, uid)) {
atomic_inc(&user->__count);
return user;
}
@@ -110,14 +112,13 @@ static void free_user(struct user_struct *up, unsigned long flags)
*
* If the user_struct could not be found, return NULL.
*/
-struct user_struct *find_user(uid_t uid)
+struct user_struct *find_user(kuid_t uid)
{
struct user_struct *ret;
unsigned long flags;
- struct user_namespace *ns = current_user_ns();
spin_lock_irqsave(&uidhash_lock, flags);
- ret = uid_hash_find(uid, uidhashentry(ns, uid));
+ ret = uid_hash_find(uid, uidhashentry(uid));
spin_unlock_irqrestore(&uidhash_lock, flags);
return ret;
}
@@ -136,9 +137,9 @@ void free_uid(struct user_struct *up)
local_irq_restore(flags);
}
-struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
+struct user_struct *alloc_uid(kuid_t uid)
{
- struct hlist_head *hashent = uidhashentry(ns, uid);
+ struct hlist_head *hashent = uidhashentry(uid);
struct user_struct *up, *new;
spin_lock_irq(&uidhash_lock);
@@ -153,8 +154,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
new->uid = uid;
atomic_set(&new->__count, 1);
- new->_user_ns = get_user_ns(ns);
-
/*
* Before adding this, check whether we raced
* on adding the same user already..
@@ -162,7 +161,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
spin_lock_irq(&uidhash_lock);
up = uid_hash_find(uid, hashent);
if (up) {
- put_user_ns(ns);
key_put(new->uid_keyring);
key_put(new->session_keyring);
kmem_cache_free(uid_cachep, new);
@@ -187,11 +185,11 @@ static int __init uid_cache_init(void)
0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
for(n = 0; n < UIDHASH_SZ; ++n)
- INIT_HLIST_HEAD(init_user_ns.uidhash_table + n);
+ INIT_HLIST_HEAD(uidhash_table + n);
/* Insert the root user immediately (init already runs as root) */
spin_lock_irq(&uidhash_lock);
- uid_hash_insert(&root_user, uidhashentry(&init_user_ns, 0));
+ uid_hash_insert(&root_user, uidhashentry(GLOBAL_ROOT_UID));
spin_unlock_irq(&uidhash_lock);
return 0;
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index e216e1e..898e973 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -27,7 +27,6 @@ int create_user_ns(struct cred *new)
{
struct user_namespace *ns, *parent_ns = new->user_ns;
struct user_struct *root_user;
- int n;
ns = kmem_cache_alloc(user_ns_cachep, GFP_KERNEL);
if (!ns)
@@ -35,11 +34,8 @@ int create_user_ns(struct cred *new)
kref_init(&ns->kref);
- for (n = 0; n < UIDHASH_SZ; ++n)
- INIT_HLIST_HEAD(ns->uidhash_table + n);
-
/* Alloc new root user. */
- root_user = alloc_uid(ns, 0);
+ root_user = alloc_uid(make_kuid(ns, 0));
if (!root_user) {
kmem_cache_free(user_ns_cachep, ns);
return -ENOMEM;
--
1.7.2.5
next prev parent reply other threads:[~2012-04-08 5:20 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-08 5:10 [REVIEW][PATCH 0/43] Completing the user namespace Eric W. Biederman
2012-04-08 5:14 ` [PATCH 01/43] vfs: Don't allow a user namespace root to make device nodes "Eric W. Beiderman
2012-04-08 5:14 ` [PATCH 02/43] userns: Kill bogus declaration of function release_uids "Eric W. Beiderman
2012-04-08 5:14 ` [PATCH 03/43] userns: Replace netlink uses of cap_raised with capable "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 04/43] userns: Remove unnecessary cast to struct user_struct when copying cred->user "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 05/43] cred: Add forward declaration of init_user_ns in all cases "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 06/43] userns: Use cred->user_ns instead of cred->user->user_ns "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 07/43] cred: Refcount the user_ns pointed to by the cred "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 08/43] userns: Add an explicit reference to the parent user namespace "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 09/43] mqueue: Explicitly capture the user namespace to send the notification to "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 10/43] userns: Deprecate and rename the user_namespace reference in the user_struct "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 11/43] userns: Start out with a full set of capabilities "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 12/43] userns: Replace the hard to write inode_userns with inode_capable "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 13/43] userns: Add kuid_t and kgid_t and associated infrastructure in uidgid.h "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 14/43] userns: Add a Kconfig option to enforce strict kuid and kgid type checks "Eric W. Beiderman
2012-04-08 5:15 ` "Eric W. Beiderman [this message]
2012-04-08 5:15 ` [PATCH 16/43] userns: Simplify the user_namespace by making userns->creator a kuid "Eric W. Beiderman
2012-04-18 18:48 ` Serge E. Hallyn
2012-04-20 22:58 ` Eric W. Biederman
2012-04-24 17:33 ` Serge E. Hallyn
2012-04-24 19:41 ` Eric W. Biederman
2012-04-24 20:23 ` Serge E. Hallyn
2012-04-26 9:09 ` Eric W. Biederman
2012-04-26 16:21 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 18/43] userns: Convert group_info values from gid_t to kgid_t "Eric W. Beiderman
2012-04-18 18:49 ` Serge E. Hallyn
2012-04-20 23:05 ` Eric W. Biederman
2012-04-08 5:15 ` [PATCH 19/43] userns: Store uid and gid values in struct cred with kuid_t and kgid_t types "Eric W. Beiderman
2012-04-18 18:49 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 20/43] userns: Replace user_ns_map_uid and user_ns_map_gid with from_kuid and from_kgid "Eric W. Beiderman
2012-04-18 18:49 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 21/43] userns: Convert sched_set_affinity and sched_set_scheduler's permission checks "Eric W. Beiderman
2012-04-18 18:50 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 22/43] userns: Convert capabilities related permsion checks "Eric W. Beiderman
2012-04-18 18:51 ` Serge E. Hallyn
2012-04-20 23:18 ` Eric W. Biederman
2012-04-08 5:15 ` [PATCH 23/43] userns: Convert setting and getting uid and gid system calls to use kuid and kgid "Eric W. Beiderman
2012-04-26 16:20 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 24/43] userns: Convert ptrace, kill, set_priority permission checks to work with kuids and kgids "Eric W. Beiderman
2012-04-18 18:56 ` Serge E. Hallyn
2012-04-20 23:51 ` Eric W. Biederman
2012-04-08 5:15 ` [PATCH 25/43] userns: Store uid and gid types in vfs structures with kuid_t and kgid_t types "Eric W. Beiderman
2012-04-18 18:57 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 26/43] userns: Convert in_group_p and in_egroup_p to use kgid_t "Eric W. Beiderman
2012-04-18 18:58 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 27/43] userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs "Eric W. Beiderman
2012-04-18 19:02 ` Serge E. Hallyn
2012-04-21 0:05 ` Eric W. Biederman
2012-04-18 19:03 ` Serge E. Hallyn
2012-04-21 0:58 ` Eric W. Biederman
2012-04-24 17:41 ` Serge E. Hallyn
2012-04-26 0:11 ` Serge E. Hallyn
2012-04-26 5:33 ` Eric W. Biederman
2012-04-08 5:15 ` [PATCH 28/43] userns: Convert user specfied uids and gids in chown into kuids and kgid "Eric W. Beiderman
2012-04-18 19:03 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 29/43] userns: Convert stat to return values mapped from kuids and kgids "Eric W. Beiderman
2012-04-18 19:03 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 30/43] userns: Fail exec for suid and sgid binaries with ids outside our user namespace "Eric W. Beiderman
2012-04-18 19:05 ` Serge E. Hallyn
2012-04-18 19:09 ` Serge E. Hallyn
2012-04-24 2:28 ` Eric W. Biederman
2012-04-24 15:10 ` Serge Hallyn
2012-04-08 5:15 ` [PATCH 31/43] userns: Teach inode_capable to understand inodes whose uids map to other namespaces "Eric W. Beiderman
2012-04-18 19:06 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 32/43] userns: signal remove unnecessary map_cred_ns "Eric W. Beiderman
2012-04-18 19:07 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 33/43] userns: Convert binary formats to use kuid/kgid where appropriate "Eric W. Beiderman
2012-04-18 19:10 ` Serge E. Hallyn
2012-04-24 2:44 ` Eric W. Biederman
2012-04-08 5:15 ` [PATCH 34/43] userns: Convert devpts " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 35/43] userns: Convert ext2 " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 36/43] userns: Convert ext3 " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 37/43] userns: Convert ext4 to user " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 38/43] userns: Convert proc to use " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 39/43] userns: Convert sysctl permission checks to use kuid and kgids "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 40/43] userns: Convert sysfs to use kgid/kuid where appropriate "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 41/43] userns: Convert tmpfs to use kuid and kgid " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 42/43] userns: Convert cgroup permission checks to use uid_eq "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 43/43] userns: Convert the move_pages, and migrate_pages " "Eric W. Beiderman
2012-04-08 14:54 ` [REVIEW][PATCH 0/43] Completing the user namespace Serge Hallyn
2012-04-08 17:40 ` richard -rw- weinberger
2012-04-08 21:30 ` Eric W. Biederman
2012-04-08 22:04 ` richard -rw- weinberger
2012-04-08 22:52 ` Eric W. Biederman
[not found] ` <1333862139-31737-17-git-send-email-ebiederm@xmission.com>
2012-04-18 18:49 ` [PATCH 17/43] userns: Rework the user_namespace adding uid/gid mapping support Serge E. Hallyn
2012-05-11 23:20 ` Please include user-namespace.git in linux-next Eric W. Biederman
2012-05-13 23:35 ` Stephen Rothwell
2012-05-21 2:25 ` Tetsuo Handa
2012-05-22 17:26 ` Eric W. Biederman
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