Contributors: 25
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Eric W. Biedermann |
303 |
30.95% |
12 |
19.35% |
| Giuseppe Scrivano |
96 |
9.81% |
1 |
1.61% |
| Pavel Emelyanov |
88 |
8.99% |
1 |
1.61% |
| Serge E. Hallyn |
81 |
8.27% |
4 |
6.45% |
| Al Viro |
72 |
7.35% |
6 |
9.68% |
| Kirill Korotaev |
57 |
5.82% |
3 |
4.84% |
| Pierre Peiffer |
54 |
5.52% |
2 |
3.23% |
| Alexey Gladkov |
44 |
4.49% |
3 |
4.84% |
| Nadia Derbey |
37 |
3.78% |
3 |
4.84% |
| Rik Van Riel |
32 |
3.27% |
2 |
3.23% |
| Alexey Dobriyan |
27 |
2.76% |
3 |
4.84% |
| Andrey Vagin |
18 |
1.84% |
1 |
1.61% |
| Christian Brauner |
16 |
1.63% |
1 |
1.61% |
| Davidlohr Bueso A |
8 |
0.82% |
4 |
6.45% |
| Linus Torvalds (pre-git) |
8 |
0.82% |
3 |
4.84% |
| Cédric Le Goater |
7 |
0.72% |
1 |
1.61% |
| Andrew Morton |
6 |
0.61% |
2 |
3.23% |
| Ingo Molnar |
6 |
0.61% |
2 |
3.23% |
| Xiaotian Feng |
5 |
0.51% |
1 |
1.61% |
| Kirill V Tkhai |
4 |
0.41% |
1 |
1.61% |
| Jiebin Sun |
4 |
0.41% |
1 |
1.61% |
| Elena Reshetova |
2 |
0.20% |
1 |
1.61% |
| David Howells |
2 |
0.20% |
2 |
3.23% |
| Greg Kroah-Hartman |
1 |
0.10% |
1 |
1.61% |
| Vasily Averin |
1 |
0.10% |
1 |
1.61% |
| Total |
979 |
|
62 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* linux/ipc/namespace.c
* Copyright (C) 2006 Pavel Emelyanov <xemul@openvz.org> OpenVZ, SWsoft Inc.
*/
#include <linux/ipc.h>
#include <linux/msg.h>
#include <linux/ipc_namespace.h>
#include <linux/rcupdate.h>
#include <linux/nsproxy.h>
#include <linux/slab.h>
#include <linux/cred.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/user_namespace.h>
#include <linux/proc_ns.h>
#include <linux/sched/task.h>
#include "util.h"
/*
* The work queue is used to avoid the cost of synchronize_rcu in kern_unmount.
*/
static void free_ipc(struct work_struct *unused);
static DECLARE_WORK(free_ipc_work, free_ipc);
static struct ucounts *inc_ipc_namespaces(struct user_namespace *ns)
{
return inc_ucount(ns, current_euid(), UCOUNT_IPC_NAMESPACES);
}
static void dec_ipc_namespaces(struct ucounts *ucounts)
{
dec_ucount(ucounts, UCOUNT_IPC_NAMESPACES);
}
static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
struct ipc_namespace *old_ns)
{
struct ipc_namespace *ns;
struct ucounts *ucounts;
int err;
err = -ENOSPC;
again:
ucounts = inc_ipc_namespaces(user_ns);
if (!ucounts) {
/*
* IPC namespaces are freed asynchronously, by free_ipc_work.
* If frees were pending, flush_work will wait, and
* return true. Fail the allocation if no frees are pending.
*/
if (flush_work(&free_ipc_work))
goto again;
goto fail;
}
err = -ENOMEM;
ns = kzalloc(sizeof(struct ipc_namespace), GFP_KERNEL_ACCOUNT);
if (ns == NULL)
goto fail_dec;
err = ns_alloc_inum(&ns->ns);
if (err)
goto fail_free;
ns->ns.ops = &ipcns_operations;
refcount_set(&ns->ns.count, 1);
ns->user_ns = get_user_ns(user_ns);
ns->ucounts = ucounts;
err = mq_init_ns(ns);
if (err)
goto fail_put;
err = -ENOMEM;
if (!setup_mq_sysctls(ns))
goto fail_put;
if (!setup_ipc_sysctls(ns))
goto fail_mq;
err = msg_init_ns(ns);
if (err)
goto fail_put;
sem_init_ns(ns);
shm_init_ns(ns);
return ns;
fail_mq:
retire_mq_sysctls(ns);
fail_put:
put_user_ns(ns->user_ns);
ns_free_inum(&ns->ns);
fail_free:
kfree(ns);
fail_dec:
dec_ipc_namespaces(ucounts);
fail:
return ERR_PTR(err);
}
struct ipc_namespace *copy_ipcs(unsigned long flags,
struct user_namespace *user_ns, struct ipc_namespace *ns)
{
if (!(flags & CLONE_NEWIPC))
return get_ipc_ns(ns);
return create_ipc_ns(user_ns, ns);
}
/*
* free_ipcs - free all ipcs of one type
* @ns: the namespace to remove the ipcs from
* @ids: the table of ipcs to free
* @free: the function called to free each individual ipc
*
* Called for each kind of ipc when an ipc_namespace exits.
*/
void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
void (*free)(struct ipc_namespace *, struct kern_ipc_perm *))
{
struct kern_ipc_perm *perm;
int next_id;
int total, in_use;
down_write(&ids->rwsem);
in_use = ids->in_use;
for (total = 0, next_id = 0; total < in_use; next_id++) {
perm = idr_find(&ids->ipcs_idr, next_id);
if (perm == NULL)
continue;
rcu_read_lock();
ipc_lock_object(perm);
free(ns, perm);
total++;
}
up_write(&ids->rwsem);
}
static void free_ipc_ns(struct ipc_namespace *ns)
{
/*
* Caller needs to wait for an RCU grace period to have passed
* after making the mount point inaccessible to new accesses.
*/
mntput(ns->mq_mnt);
sem_exit_ns(ns);
msg_exit_ns(ns);
shm_exit_ns(ns);
retire_mq_sysctls(ns);
retire_ipc_sysctls(ns);
dec_ipc_namespaces(ns->ucounts);
put_user_ns(ns->user_ns);
ns_free_inum(&ns->ns);
kfree(ns);
}
static LLIST_HEAD(free_ipc_list);
static void free_ipc(struct work_struct *unused)
{
struct llist_node *node = llist_del_all(&free_ipc_list);
struct ipc_namespace *n, *t;
llist_for_each_entry_safe(n, t, node, mnt_llist)
mnt_make_shortterm(n->mq_mnt);
/* Wait for any last users to have gone away. */
synchronize_rcu();
llist_for_each_entry_safe(n, t, node, mnt_llist)
free_ipc_ns(n);
}
/*
* put_ipc_ns - drop a reference to an ipc namespace.
* @ns: the namespace to put
*
* If this is the last task in the namespace exiting, and
* it is dropping the refcount to 0, then it can race with
* a task in another ipc namespace but in a mounts namespace
* which has this ipcns's mqueuefs mounted, doing some action
* with one of the mqueuefs files. That can raise the refcount.
* So dropping the refcount, and raising the refcount when
* accessing it through the VFS, are protected with mq_lock.
*
* (Clearly, a task raising the refcount on its own ipc_ns
* needn't take mq_lock since it can't race with the last task
* in the ipcns exiting).
*/
void put_ipc_ns(struct ipc_namespace *ns)
{
if (refcount_dec_and_lock(&ns->ns.count, &mq_lock)) {
mq_clear_sbinfo(ns);
spin_unlock(&mq_lock);
if (llist_add(&ns->mnt_llist, &free_ipc_list))
schedule_work(&free_ipc_work);
}
}
static inline struct ipc_namespace *to_ipc_ns(struct ns_common *ns)
{
return container_of(ns, struct ipc_namespace, ns);
}
static struct ns_common *ipcns_get(struct task_struct *task)
{
struct ipc_namespace *ns = NULL;
struct nsproxy *nsproxy;
task_lock(task);
nsproxy = task->nsproxy;
if (nsproxy)
ns = get_ipc_ns(nsproxy->ipc_ns);
task_unlock(task);
return ns ? &ns->ns : NULL;
}
static void ipcns_put(struct ns_common *ns)
{
return put_ipc_ns(to_ipc_ns(ns));
}
static int ipcns_install(struct nsset *nsset, struct ns_common *new)
{
struct nsproxy *nsproxy = nsset->nsproxy;
struct ipc_namespace *ns = to_ipc_ns(new);
if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
!ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN))
return -EPERM;
put_ipc_ns(nsproxy->ipc_ns);
nsproxy->ipc_ns = get_ipc_ns(ns);
return 0;
}
static struct user_namespace *ipcns_owner(struct ns_common *ns)
{
return to_ipc_ns(ns)->user_ns;
}
const struct proc_ns_operations ipcns_operations = {
.name = "ipc",
.type = CLONE_NEWIPC,
.get = ipcns_get,
.put = ipcns_put,
.install = ipcns_install,
.owner = ipcns_owner,
};