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authorAl Viro <viro@zeniv.linux.org.uk>2008-07-22 13:59:21 (GMT)
committerAl Viro <viro@zeniv.linux.org.uk>2008-07-27 00:53:34 (GMT)
commit2d8f30380ab8c706f4e0a8f1aaa22b5886e9ac8a (patch)
treeb798097fd831eab39f35c8c2e5a8ccfd7a850ef5 /fs/namespace.c
parent256984a83880ff7ac78055cb87baea48137f0b77 (diff)
downloadlinux-2d8f30380ab8c706f4e0a8f1aaa22b5886e9ac8a.tar.xz
[PATCH] sanitize __user_walk_fd() et.al.
* do not pass nameidata; struct path is all the callers want. * switch to new helpers: user_path_at(dfd, pathname, flags, &path) user_path(pathname, &path) user_lpath(pathname, &path) user_path_dir(pathname, &path) (fail if not a directory) The last 3 are trivial macro wrappers for the first one. * remove nameidata in callers. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namespace.c')
-rw-r--r--fs/namespace.c74
1 files changed, 36 insertions, 38 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 26380f5..411728c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1130,27 +1130,27 @@ static int do_umount(struct vfsmount *mnt, int flags)
asmlinkage long sys_umount(char __user * name, int flags)
{
- struct nameidata nd;
+ struct path path;
int retval;
- retval = __user_walk(name, LOOKUP_FOLLOW, &nd);
+ retval = user_path(name, &path);
if (retval)
goto out;
retval = -EINVAL;
- if (nd.path.dentry != nd.path.mnt->mnt_root)
+ if (path.dentry != path.mnt->mnt_root)
goto dput_and_out;
- if (!check_mnt(nd.path.mnt))
+ if (!check_mnt(path.mnt))
goto dput_and_out;
retval = -EPERM;
if (!capable(CAP_SYS_ADMIN))
goto dput_and_out;
- retval = do_umount(nd.path.mnt, flags);
+ retval = do_umount(path.mnt, flags);
dput_and_out:
/* we mustn't call path_put() as that would clear mnt_expiry_mark */
- dput(nd.path.dentry);
- mntput_no_expire(nd.path.mnt);
+ dput(path.dentry);
+ mntput_no_expire(path.mnt);
out:
return retval;
}
@@ -2179,28 +2179,26 @@ asmlinkage long sys_pivot_root(const char __user * new_root,
const char __user * put_old)
{
struct vfsmount *tmp;
- struct nameidata new_nd, old_nd;
- struct path parent_path, root_parent, root;
+ struct path new, old, parent_path, root_parent, root;
int error;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- error = __user_walk(new_root, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
- &new_nd);
+ error = user_path_dir(new_root, &new);
if (error)
goto out0;
error = -EINVAL;
- if (!check_mnt(new_nd.path.mnt))
+ if (!check_mnt(new.mnt))
goto out1;
- error = __user_walk(put_old, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &old_nd);
+ error = user_path_dir(put_old, &old);
if (error)
goto out1;
- error = security_sb_pivotroot(&old_nd.path, &new_nd.path);
+ error = security_sb_pivotroot(&old, &new);
if (error) {
- path_put(&old_nd.path);
+ path_put(&old);
goto out1;
}
@@ -2209,69 +2207,69 @@ asmlinkage long sys_pivot_root(const char __user * new_root,
path_get(&current->fs->root);
read_unlock(&current->fs->lock);
down_write(&namespace_sem);
- mutex_lock(&old_nd.path.dentry->d_inode->i_mutex);
+ mutex_lock(&old.dentry->d_inode->i_mutex);
error = -EINVAL;
- if (IS_MNT_SHARED(old_nd.path.mnt) ||
- IS_MNT_SHARED(new_nd.path.mnt->mnt_parent) ||
+ if (IS_MNT_SHARED(old.mnt) ||
+ IS_MNT_SHARED(new.mnt->mnt_parent) ||
IS_MNT_SHARED(root.mnt->mnt_parent))
goto out2;
if (!check_mnt(root.mnt))
goto out2;
error = -ENOENT;
- if (IS_DEADDIR(new_nd.path.dentry->d_inode))
+ if (IS_DEADDIR(new.dentry->d_inode))
goto out2;
- if (d_unhashed(new_nd.path.dentry) && !IS_ROOT(new_nd.path.dentry))
+ if (d_unhashed(new.dentry) && !IS_ROOT(new.dentry))
goto out2;
- if (d_unhashed(old_nd.path.dentry) && !IS_ROOT(old_nd.path.dentry))
+ if (d_unhashed(old.dentry) && !IS_ROOT(old.dentry))
goto out2;
error = -EBUSY;
- if (new_nd.path.mnt == root.mnt ||
- old_nd.path.mnt == root.mnt)
+ if (new.mnt == root.mnt ||
+ old.mnt == root.mnt)
goto out2; /* loop, on the same file system */
error = -EINVAL;
if (root.mnt->mnt_root != root.dentry)
goto out2; /* not a mountpoint */
if (root.mnt->mnt_parent == root.mnt)
goto out2; /* not attached */
- if (new_nd.path.mnt->mnt_root != new_nd.path.dentry)
+ if (new.mnt->mnt_root != new.dentry)
goto out2; /* not a mountpoint */
- if (new_nd.path.mnt->mnt_parent == new_nd.path.mnt)
+ if (new.mnt->mnt_parent == new.mnt)
goto out2; /* not attached */
/* make sure we can reach put_old from new_root */
- tmp = old_nd.path.mnt;
+ tmp = old.mnt;
spin_lock(&vfsmount_lock);
- if (tmp != new_nd.path.mnt) {
+ if (tmp != new.mnt) {
for (;;) {
if (tmp->mnt_parent == tmp)
goto out3; /* already mounted on put_old */
- if (tmp->mnt_parent == new_nd.path.mnt)
+ if (tmp->mnt_parent == new.mnt)
break;
tmp = tmp->mnt_parent;
}
- if (!is_subdir(tmp->mnt_mountpoint, new_nd.path.dentry))
+ if (!is_subdir(tmp->mnt_mountpoint, new.dentry))
goto out3;
- } else if (!is_subdir(old_nd.path.dentry, new_nd.path.dentry))
+ } else if (!is_subdir(old.dentry, new.dentry))
goto out3;
- detach_mnt(new_nd.path.mnt, &parent_path);
+ detach_mnt(new.mnt, &parent_path);
detach_mnt(root.mnt, &root_parent);
/* mount old root on put_old */
- attach_mnt(root.mnt, &old_nd.path);
+ attach_mnt(root.mnt, &old);
/* mount new_root on / */
- attach_mnt(new_nd.path.mnt, &root_parent);
+ attach_mnt(new.mnt, &root_parent);
touch_mnt_namespace(current->nsproxy->mnt_ns);
spin_unlock(&vfsmount_lock);
- chroot_fs_refs(&root, &new_nd.path);
- security_sb_post_pivotroot(&root, &new_nd.path);
+ chroot_fs_refs(&root, &new);
+ security_sb_post_pivotroot(&root, &new);
error = 0;
path_put(&root_parent);
path_put(&parent_path);
out2:
- mutex_unlock(&old_nd.path.dentry->d_inode->i_mutex);
+ mutex_unlock(&old.dentry->d_inode->i_mutex);
up_write(&namespace_sem);
path_put(&root);
- path_put(&old_nd.path);
+ path_put(&old);
out1:
- path_put(&new_nd.path);
+ path_put(&new);
out0:
return error;
out3: