From 2d8f30380ab8c706f4e0a8f1aaa22b5886e9ac8a Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Tue, 22 Jul 2008 09:59:21 -0400
Subject: [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>
---
 fs/stat.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

(limited to 'fs/stat.c')

diff --git a/fs/stat.c b/fs/stat.c
index 9cf41f719d5..7c46fbeb8b7 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -57,13 +57,13 @@ EXPORT_SYMBOL(vfs_getattr);
 
 int vfs_stat_fd(int dfd, char __user *name, struct kstat *stat)
 {
-	struct nameidata nd;
+	struct path path;
 	int error;
 
-	error = __user_walk_fd(dfd, name, LOOKUP_FOLLOW, &nd);
+	error = user_path_at(dfd, name, LOOKUP_FOLLOW, &path);
 	if (!error) {
-		error = vfs_getattr(nd.path.mnt, nd.path.dentry, stat);
-		path_put(&nd.path);
+		error = vfs_getattr(path.mnt, path.dentry, stat);
+		path_put(&path);
 	}
 	return error;
 }
@@ -77,13 +77,13 @@ EXPORT_SYMBOL(vfs_stat);
 
 int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat)
 {
-	struct nameidata nd;
+	struct path path;
 	int error;
 
-	error = __user_walk_fd(dfd, name, 0, &nd);
+	error = user_path_at(dfd, name, 0, &path);
 	if (!error) {
-		error = vfs_getattr(nd.path.mnt, nd.path.dentry, stat);
-		path_put(&nd.path);
+		error = vfs_getattr(path.mnt, path.dentry, stat);
+		path_put(&path);
 	}
 	return error;
 }
@@ -291,29 +291,29 @@ asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf)
 	return error;
 }
 
-asmlinkage long sys_readlinkat(int dfd, const char __user *path,
+asmlinkage long sys_readlinkat(int dfd, const char __user *pathname,
 				char __user *buf, int bufsiz)
 {
-	struct nameidata nd;
+	struct path path;
 	int error;
 
 	if (bufsiz <= 0)
 		return -EINVAL;
 
-	error = __user_walk_fd(dfd, path, 0, &nd);
+	error = user_path_at(dfd, pathname, 0, &path);
 	if (!error) {
-		struct inode *inode = nd.path.dentry->d_inode;
+		struct inode *inode = path.dentry->d_inode;
 
 		error = -EINVAL;
 		if (inode->i_op && inode->i_op->readlink) {
-			error = security_inode_readlink(nd.path.dentry);
+			error = security_inode_readlink(path.dentry);
 			if (!error) {
-				touch_atime(nd.path.mnt, nd.path.dentry);
-				error = inode->i_op->readlink(nd.path.dentry,
+				touch_atime(path.mnt, path.dentry);
+				error = inode->i_op->readlink(path.dentry,
 							      buf, bufsiz);
 			}
 		}
-		path_put(&nd.path);
+		path_put(&path);
 	}
 	return error;
 }
-- 
cgit v1.2.3