From: Andreas Gruenbacher <agruen@suse.de>
Subject: Switch to vfs_permission() in sys_fchdir()

Switch from file_permission() to vfs_permission() in sys_fchdir(): this
avoids calling permission() with a NULL nameidata here.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: John Johansen <jjohansen@suse.de>

---
 fs/open.c |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

--- a/fs/open.c
+++ b/fs/open.c
@@ -512,8 +512,8 @@ out:
 
 asmlinkage long sys_fchdir(unsigned int fd)
 {
+	struct nameidata nd = { .flags = 0 };
 	struct file *file;
-	struct inode *inode;
 	int error;
 
 	error = -EBADF;
@@ -521,12 +521,11 @@ asmlinkage long sys_fchdir(unsigned int 
 	if (!file)
 		goto out;
 
-	inode = file->f_path.dentry->d_inode;
-
 	error = -ENOTDIR;
-	if (!S_ISDIR(inode->i_mode))
+	if (!S_ISDIR(file->f_path.dentry->d_inode->i_mode))
 		goto out_putf;
 
+	nd.path = file->f_path;
 	error = file_permission(file, MAY_EXEC);
 	if (!error)
 		set_fs_pwd(current->fs, &file->f_path);