Commit ddf75ae3 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull namespace fixes from Eric Biederman:
 "This tree includes two bug fixes for problems Oleg spotted on his
  review of the recent pid namespace work.  A small fix to not enable
  bottom halves with irqs disabled, and a trivial build fix for f2fs
  with user namespaces enabled."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  f2fs: Don't assign e_id in f2fs_acl_from_disk
  proc: Allow proc_free_inum to be called from any context
  pidns: Stop pid allocation when init dies
  pidns: Outlaw thread creation after unshare(CLONE_NEWPID)
parents 7fd83b47 48c6d121
......@@ -82,7 +82,6 @@ static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry_short));
break;
......
......@@ -352,18 +352,18 @@ retry:
if (!ida_pre_get(&proc_inum_ida, GFP_KERNEL))
return -ENOMEM;
spin_lock_bh(&proc_inum_lock);
spin_lock_irq(&proc_inum_lock);
error = ida_get_new(&proc_inum_ida, &i);
spin_unlock_bh(&proc_inum_lock);
spin_unlock_irq(&proc_inum_lock);
if (error == -EAGAIN)
goto retry;
else if (error)
return error;
if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
spin_lock_bh(&proc_inum_lock);
spin_lock_irq(&proc_inum_lock);
ida_remove(&proc_inum_ida, i);
spin_unlock_bh(&proc_inum_lock);
spin_unlock_irq(&proc_inum_lock);
return -ENOSPC;
}
*inum = PROC_DYNAMIC_FIRST + i;
......@@ -372,9 +372,10 @@ retry:
void proc_free_inum(unsigned int inum)
{
spin_lock_bh(&proc_inum_lock);
unsigned long flags;
spin_lock_irqsave(&proc_inum_lock, flags);
ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
spin_unlock_bh(&proc_inum_lock);
spin_unlock_irqrestore(&proc_inum_lock, flags);
}
static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
......
......@@ -121,6 +121,7 @@ int next_pidmap(struct pid_namespace *pid_ns, unsigned int last);
extern struct pid *alloc_pid(struct pid_namespace *ns);
extern void free_pid(struct pid *pid);
extern void disable_pid_allocation(struct pid_namespace *ns);
/*
* ns_of_pid() returns the pid namespace in which the specified pid was
......
......@@ -21,7 +21,7 @@ struct pid_namespace {
struct kref kref;
struct pidmap pidmap[PIDMAP_ENTRIES];
int last_pid;
int nr_hashed;
unsigned int nr_hashed;
struct task_struct *child_reaper;
struct kmem_cache *pid_cachep;
unsigned int level;
......@@ -42,6 +42,8 @@ struct pid_namespace {
extern struct pid_namespace init_pid_ns;
#define PIDNS_HASH_ADDING (1U << 31)
#ifdef CONFIG_PID_NS
static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
{
......
......@@ -1166,6 +1166,14 @@ static struct task_struct *copy_process(unsigned long clone_flags,
current->signal->flags & SIGNAL_UNKILLABLE)
return ERR_PTR(-EINVAL);
/*
* If the new process will be in a different pid namespace
* don't allow the creation of threads.
*/
if ((clone_flags & (CLONE_VM|CLONE_NEWPID)) &&
(task_active_pid_ns(current) != current->nsproxy->pid_ns))
return ERR_PTR(-EINVAL);
retval = security_task_create(clone_flags);
if (retval)
goto fork_out;
......
......@@ -270,7 +270,6 @@ void free_pid(struct pid *pid)
wake_up_process(ns->child_reaper);
break;
case 0:
ns->nr_hashed = -1;
schedule_work(&ns->proc_work);
break;
}
......@@ -319,7 +318,7 @@ struct pid *alloc_pid(struct pid_namespace *ns)
upid = pid->numbers + ns->level;
spin_lock_irq(&pidmap_lock);
if (ns->nr_hashed < 0)
if (!(ns->nr_hashed & PIDNS_HASH_ADDING))
goto out_unlock;
for ( ; upid >= pid->numbers; --upid) {
hlist_add_head_rcu(&upid->pid_chain,
......@@ -342,6 +341,13 @@ out_free:
goto out;
}
void disable_pid_allocation(struct pid_namespace *ns)
{
spin_lock_irq(&pidmap_lock);
ns->nr_hashed &= ~PIDNS_HASH_ADDING;
spin_unlock_irq(&pidmap_lock);
}
struct pid *find_pid_ns(int nr, struct pid_namespace *ns)
{
struct hlist_node *elem;
......@@ -573,6 +579,9 @@ void __init pidhash_init(void)
void __init pidmap_init(void)
{
/* Veryify no one has done anything silly */
BUILD_BUG_ON(PID_MAX_LIMIT >= PIDNS_HASH_ADDING);
/* bump default and minimum pid_max based on number of cpus */
pid_max = min(pid_max_max, max_t(int, pid_max,
PIDS_PER_CPU_DEFAULT * num_possible_cpus()));
......@@ -584,7 +593,7 @@ void __init pidmap_init(void)
/* Reserve PID 0. We never call free_pidmap(0) */
set_bit(0, init_pid_ns.pidmap[0].page);
atomic_dec(&init_pid_ns.pidmap[0].nr_free);
init_pid_ns.nr_hashed = 1;
init_pid_ns.nr_hashed = PIDNS_HASH_ADDING;
init_pid_ns.pid_cachep = KMEM_CACHE(pid,
SLAB_HWCACHE_ALIGN | SLAB_PANIC);
......
......@@ -115,6 +115,7 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns
ns->level = level;
ns->parent = get_pid_ns(parent_pid_ns);
ns->user_ns = get_user_ns(user_ns);
ns->nr_hashed = PIDNS_HASH_ADDING;
INIT_WORK(&ns->proc_work, proc_cleanup_work);
set_bit(0, ns->pidmap[0].page);
......@@ -181,6 +182,9 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
int rc;
struct task_struct *task, *me = current;
/* Don't allow any more processes into the pid namespace */
disable_pid_allocation(pid_ns);
/* Ignore SIGCHLD causing any terminated children to autoreap */
spin_lock_irq(&me->sighand->siglock);
me->sighand->action[SIGCHLD - 1].sa.sa_handler = SIG_IGN;
......
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