mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-24 05:04:00 +08:00
57e8391d32
- Pid namespaces are designed to be inescapable so verify that the passed in pid namespace is a child of the currently active pid namespace or the currently active pid namespace itself. Allowing the currently active pid namespace is important so the effects of an earlier setns can be cancelled. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
204 lines
4.2 KiB
C
204 lines
4.2 KiB
C
#include <linux/proc_fs.h>
|
|
#include <linux/nsproxy.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/fs_struct.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/path.h>
|
|
#include <linux/namei.h>
|
|
#include <linux/file.h>
|
|
#include <linux/utsname.h>
|
|
#include <net/net_namespace.h>
|
|
#include <linux/ipc_namespace.h>
|
|
#include <linux/pid_namespace.h>
|
|
#include "internal.h"
|
|
|
|
|
|
static const struct proc_ns_operations *ns_entries[] = {
|
|
#ifdef CONFIG_NET_NS
|
|
&netns_operations,
|
|
#endif
|
|
#ifdef CONFIG_UTS_NS
|
|
&utsns_operations,
|
|
#endif
|
|
#ifdef CONFIG_IPC_NS
|
|
&ipcns_operations,
|
|
#endif
|
|
#ifdef CONFIG_PID_NS
|
|
&pidns_operations,
|
|
#endif
|
|
};
|
|
|
|
static const struct file_operations ns_file_operations = {
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
static struct dentry *proc_ns_instantiate(struct inode *dir,
|
|
struct dentry *dentry, struct task_struct *task, const void *ptr)
|
|
{
|
|
const struct proc_ns_operations *ns_ops = ptr;
|
|
struct inode *inode;
|
|
struct proc_inode *ei;
|
|
struct dentry *error = ERR_PTR(-ENOENT);
|
|
void *ns;
|
|
|
|
inode = proc_pid_make_inode(dir->i_sb, task);
|
|
if (!inode)
|
|
goto out;
|
|
|
|
ns = ns_ops->get(task);
|
|
if (!ns)
|
|
goto out_iput;
|
|
|
|
ei = PROC_I(inode);
|
|
inode->i_mode = S_IFREG|S_IRUSR;
|
|
inode->i_fop = &ns_file_operations;
|
|
ei->ns_ops = ns_ops;
|
|
ei->ns = ns;
|
|
|
|
d_set_d_op(dentry, &pid_dentry_operations);
|
|
d_add(dentry, inode);
|
|
/* Close the race of the process dying before we return the dentry */
|
|
if (pid_revalidate(dentry, 0))
|
|
error = NULL;
|
|
out:
|
|
return error;
|
|
out_iput:
|
|
iput(inode);
|
|
goto out;
|
|
}
|
|
|
|
static int proc_ns_fill_cache(struct file *filp, void *dirent,
|
|
filldir_t filldir, struct task_struct *task,
|
|
const struct proc_ns_operations *ops)
|
|
{
|
|
return proc_fill_cache(filp, dirent, filldir,
|
|
ops->name, strlen(ops->name),
|
|
proc_ns_instantiate, task, ops);
|
|
}
|
|
|
|
static int proc_ns_dir_readdir(struct file *filp, void *dirent,
|
|
filldir_t filldir)
|
|
{
|
|
int i;
|
|
struct dentry *dentry = filp->f_path.dentry;
|
|
struct inode *inode = dentry->d_inode;
|
|
struct task_struct *task = get_proc_task(inode);
|
|
const struct proc_ns_operations **entry, **last;
|
|
ino_t ino;
|
|
int ret;
|
|
|
|
ret = -ENOENT;
|
|
if (!task)
|
|
goto out_no_task;
|
|
|
|
ret = -EPERM;
|
|
if (!ptrace_may_access(task, PTRACE_MODE_READ))
|
|
goto out;
|
|
|
|
ret = 0;
|
|
i = filp->f_pos;
|
|
switch (i) {
|
|
case 0:
|
|
ino = inode->i_ino;
|
|
if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
|
|
goto out;
|
|
i++;
|
|
filp->f_pos++;
|
|
/* fall through */
|
|
case 1:
|
|
ino = parent_ino(dentry);
|
|
if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
|
|
goto out;
|
|
i++;
|
|
filp->f_pos++;
|
|
/* fall through */
|
|
default:
|
|
i -= 2;
|
|
if (i >= ARRAY_SIZE(ns_entries)) {
|
|
ret = 1;
|
|
goto out;
|
|
}
|
|
entry = ns_entries + i;
|
|
last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
|
|
while (entry <= last) {
|
|
if (proc_ns_fill_cache(filp, dirent, filldir,
|
|
task, *entry) < 0)
|
|
goto out;
|
|
filp->f_pos++;
|
|
entry++;
|
|
}
|
|
}
|
|
|
|
ret = 1;
|
|
out:
|
|
put_task_struct(task);
|
|
out_no_task:
|
|
return ret;
|
|
}
|
|
|
|
const struct file_operations proc_ns_dir_operations = {
|
|
.read = generic_read_dir,
|
|
.readdir = proc_ns_dir_readdir,
|
|
};
|
|
|
|
static struct dentry *proc_ns_dir_lookup(struct inode *dir,
|
|
struct dentry *dentry, unsigned int flags)
|
|
{
|
|
struct dentry *error;
|
|
struct task_struct *task = get_proc_task(dir);
|
|
const struct proc_ns_operations **entry, **last;
|
|
unsigned int len = dentry->d_name.len;
|
|
|
|
error = ERR_PTR(-ENOENT);
|
|
|
|
if (!task)
|
|
goto out_no_task;
|
|
|
|
error = ERR_PTR(-EPERM);
|
|
if (!ptrace_may_access(task, PTRACE_MODE_READ))
|
|
goto out;
|
|
|
|
last = &ns_entries[ARRAY_SIZE(ns_entries)];
|
|
for (entry = ns_entries; entry < last; entry++) {
|
|
if (strlen((*entry)->name) != len)
|
|
continue;
|
|
if (!memcmp(dentry->d_name.name, (*entry)->name, len))
|
|
break;
|
|
}
|
|
error = ERR_PTR(-ENOENT);
|
|
if (entry == last)
|
|
goto out;
|
|
|
|
error = proc_ns_instantiate(dir, dentry, task, *entry);
|
|
out:
|
|
put_task_struct(task);
|
|
out_no_task:
|
|
return error;
|
|
}
|
|
|
|
const struct inode_operations proc_ns_dir_inode_operations = {
|
|
.lookup = proc_ns_dir_lookup,
|
|
.getattr = pid_getattr,
|
|
.setattr = proc_setattr,
|
|
};
|
|
|
|
struct file *proc_ns_fget(int fd)
|
|
{
|
|
struct file *file;
|
|
|
|
file = fget(fd);
|
|
if (!file)
|
|
return ERR_PTR(-EBADF);
|
|
|
|
if (file->f_op != &ns_file_operations)
|
|
goto out_invalid;
|
|
|
|
return file;
|
|
|
|
out_invalid:
|
|
fput(file);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|