mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 10:32:35 +00:00
793925334f
Don't call iput with the inode half setup to be a namespace filedescriptor. Instead rearrange the code so that we don't initialize ei->ns_ops until after I ns_ops->get succeeds, preventing us from invoking ns_ops->put when ns_ops->get failed. Reported-by: Ingo Saitz <Ingo.Saitz@stud.uni-hannover.de> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
202 lines
4.1 KiB
C
202 lines
4.1 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/mnt_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
|
|
};
|
|
|
|
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;
|
|
|
|
dentry->d_op = &pid_dentry_operations;
|
|
d_add(dentry, inode);
|
|
/* Close the race of the process dying before we return the dentry */
|
|
if (pid_revalidate(dentry, NULL))
|
|
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, struct nameidata *nd)
|
|
{
|
|
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) - 1];
|
|
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);
|
|
}
|
|
|