Commit a62d5ee1 authored by Eric M. Ludlam's avatar Eric M. Ludlam Committed by Chong Yidong
Browse files

Fix EDE security flaw involving loading arbitrary Lisp from Project.ede.

* lisp/ede.el (ede-project-directories): New option.
(ede-directory-safe-p): Check it.
(ede-initialize-state-current-buffer, ede, ede-new)
(ede-check-project-directory, ede-rescan-toplevel)
(ede-load-project-file, ede-parent-project, ede-current-project):
(ede-target-parent): Avoid loading in a project unless it is safe,
since it may involve malicious code.  This security flaw was
pointed out by Hiroshi Oota.

* lisp/ede/auto.el (ede-project-autoload): Add safe-p slot.
(ede-project-class-files): Projects using Project.ede are unsafe.
(ede-auto-load-project): New method.

* lisp/ede/simple.el (ede-project-class-files): Mark as unsafe.
parent 866b58d6
2012-01-09 Eric Ludlam <zappo@gnu.org>
* ede.el (ede-project-directories): New option.
(ede-directory-safe-p): Check it.
(ede-initialize-state-current-buffer, ede, ede-new)
(ede-check-project-directory, ede-rescan-toplevel)
(ede-load-project-file, ede-parent-project, ede-current-project):
(ede-target-parent): Avoid loading in a project unless it is safe,
since it may involve malicious code. This security flaw was
pointed out by Hiroshi Oota.
* ede/auto.el (ede-project-autoload): Add safe-p slot.
(ede-project-class-files): Projects using Project.ede are unsafe.
(ede-auto-load-project): New method.
* ede/simple.el (ede-project-class-files): Mark as unsafe.
2011-04-13 Juanma Barranquero <lekktu@gmail.com>
* ede/pconf.el (ede-proj-tweak-autoconf, ede-proj-flush-autoconf):
......
......@@ -94,6 +94,42 @@ target willing to take the file. 'never means never perform the check."
:group 'ede
:type 'sexp) ; make this be a list of options some day
(defcustom ede-project-directories nil
"Directories in which EDE may search for project files.
If the value is t, EDE may search in any directory.
If the value is a function, EDE calls that function with one
argument, the directory name; the function should return t iff
EDE should look for project files in the directory.
Otherwise, the value should be a list of fully-expanded directory
names. EDE searches for project files only in those directories.
If you invoke the commands \\[ede] or \\[ede-new] on a directory
that is not listed, Emacs will offer to add it to the list.
Any other value disables searching for EDE project files."
:group 'ede
:type '(choice (const :tag "Any directory" t)
(repeat :tag "List of directories"
(directory))
(function :tag "Predicate"))
:version "23.4"
:risky t)
(defun ede-directory-safe-p (dir)
"Return non-nil if DIR is a safe directory to load projects from.
Projects that do not load a project definition as Emacs Lisp code
are safe, and can be loaded automatically. Other project types,
such as those created with Project.ede files, are safe only if
specified by `ede-project-directories'."
(setq dir (directory-file-name (expand-file-name dir)))
;; Load only if allowed by `ede-project-directories'.
(or (eq ede-project-directories t)
(and (functionp ede-project-directories)
(funcall ede-project-directories dir))
(and (listp ede-project-directories)
(member dir ede-project-directories))))
;;; Management variables
......@@ -419,24 +455,42 @@ provided `global-ede-mode' is enabled."
Sets buffer local variables for EDE."
(let* ((ROOT nil)
(proj (ede-directory-get-open-project default-directory
'ROOT)))
'ROOT))
(projauto nil))
(when (or proj ROOT
(ede-directory-project-p default-directory t))
;; If there is no open project, look up the project
;; autoloader to see if we should initialize.
(setq projauto (ede-directory-project-p default-directory t)))
(when (and (not proj) projauto)
;; No project was loaded, but we have a project description
;; object. This means that we can check if it is a safe
;; project to load before requesting it to be loaded.
(when (not proj)
;; @todo - this could be wasteful.
(setq proj (ede-load-project-file default-directory 'ROOT)))
(when (or (oref projauto safe-p)
;; The project style is not safe, so check if it is
;; in `ede-project-directories'.
(let ((top (ede-toplevel-project default-directory)))
(ede-directory-safe-p top)))
(setq ede-object (ede-buffer-object (current-buffer)
;; The project is safe, so load it in.
(setq proj (ede-load-project-file default-directory 'ROOT))))
;; Only initialize EDE state in this buffer if we found a project.
(when proj
(setq ede-object (ede-buffer-object (current-buffer)
'ede-object-project))
(setq ede-object-root-project
(or ROOT (ede-project-root ede-object-project)))
(setq ede-object-root-project
(or ROOT (ede-project-root ede-object-project)))
(if (and (not ede-object) ede-object-project)
(ede-auto-add-to-target))
(if (and (not ede-object) ede-object-project)
(ede-auto-add-to-target))
(ede-apply-target-options))))
(ede-apply-target-options)))))
(defun ede-reset-all-buffers (onoff)
"Reset all the buffers due to change in EDE.
......@@ -555,13 +609,73 @@ of objects with the `ede-want-file-p' method."
;;; Interactive method invocations
;;
(defun ede (file)
"Start up EDE on something.
Argument FILE is the file or directory to load a project from."
(interactive "fProject File: ")
(if (not (file-exists-p file))
(ede-new file)
(ede-load-project-file (file-name-directory file))))
(defun ede (dir)
"Start up EDE for directory DIR.
If DIR has an existing project file, load it.
Otherwise, create a new project for DIR."
(interactive
;; When choosing a directory to turn on, and we see some directory here,
;; provide that as the default.
(let* ((top (ede-toplevel-project default-directory))
(promptdflt (or top default-directory)))
(list (read-directory-name "Project directory: "
promptdflt promptdflt t))))
(unless (file-directory-p dir)
(error "%s is not a directory" dir))
(when (ede-directory-get-open-project dir)
(error "%s already has an open project associated with it" dir))
;; Check if the directory has been added to the list of safe
;; directories. It can also add the directory to the safe list if
;; the user chooses.
(if (ede-check-project-directory dir)
(progn
;; If there is a project in DIR, load it, otherwise do
;; nothing.
(ede-load-project-file dir)
;; Check if we loaded anything on the previous line.
(if (ede-current-project dir)
;; We successfully opened an existing project. Some open
;; buffers may also be referring to this project.
;; Resetting all the buffers will get them to also point
;; at this new open project.
(ede-reset-all-buffers 1)
;; ELSE
;; There was no project, so switch to `ede-new' which is how
;; a user can select a new kind of project to create.
(let ((default-directory (expand-file-name dir)))
(call-interactively 'ede-new))))
;; If the proposed directory isn't safe, then say so.
(error "%s is not an allowed project directory in `ede-project-directories'"
dir)))
(defun ede-check-project-directory (dir)
"Check if DIR should be in `ede-project-directories'.
If it is not, try asking the user if it should be added; if so,
add it and save `ede-project-directories' via Customize.
Return nil iff DIR should not be in `ede-project-directories'."
(setq dir (directory-file-name (expand-file-name dir))) ; strip trailing /
(or (eq ede-project-directories t)
(and (functionp ede-project-directories)
(funcall ede-project-directories dir))
;; If `ede-project-directories' is a list, maybe add it.
(when (listp ede-project-directories)
(or (member dir ede-project-directories)
(when (y-or-n-p (format "`%s' is not listed in `ede-project-directories'.
Add it to the list of allowed project directories? "
dir))
(push dir ede-project-directories)
;; If possible, save `ede-project-directories'.
(if (or custom-file user-init-file)
(let ((coding-system-for-read nil))
(customize-save-variable
'ede-project-directories
ede-project-directories)))
t)))))
(defun ede-new (type &optional name)
"Create a new project starting of project type TYPE.
......@@ -596,6 +710,11 @@ Optional argument NAME is the name to give this project."
(error "Cannot create project in non-existent directory %s" default-directory))
(when (not (file-writable-p default-directory))
(error "No write permissions for %s" default-directory))
(unless (ede-check-project-directory default-directory)
(error "%s is not an allowed project directory in `ede-project-directories'"
default-directory))
;; Make sure the project directory is loadable in the future.
(ede-check-project-directory default-directory)
;; Create the project
(let* ((obj (object-assoc type 'name ede-project-class-files))
(nobj (let ((f (oref obj file))
......@@ -629,6 +748,10 @@ Optional argument NAME is the name to give this project."
(ede-add-subproject pp nobj)
(ede-commit-project pp)))
(ede-commit-project nobj))
;; Once the project is created, load it again. This used to happen
;; lazily, but with project loading occurring less often and with
;; security in mind, this is now the safe time to reload.
(ede-load-project-file default-directory)
;; Have the menu appear
(setq ede-minor-mode t)
;; Allert the user
......@@ -651,11 +774,16 @@ ARGS are additional arguments to pass to method sym."
(defun ede-rescan-toplevel ()
"Rescan all project files."
(interactive)
(let ((toppath (ede-toplevel-project default-directory))
(ede-deep-rescan t))
(project-rescan (ede-load-project-file toppath))
(ede-reset-all-buffers 1)
))
(if (not (ede-directory-get-open-project default-directory))
;; This directory isn't open. Can't rescan.
(error "Attempt to rescan a project that isn't open")
;; Continue
(let ((toppath (ede-toplevel-project default-directory))
(ede-deep-rescan t))
(project-rescan (ede-load-project-file toppath))
(ede-reset-all-buffers 1))))
(defun ede-new-target (&rest args)
"Create a new target specific to this type of project file.
......@@ -891,7 +1019,7 @@ Optional ROOTRETURN will return the root project for DIR."
;; Do the load
;;(message "EDE LOAD : %S" file)
(let* ((file dir)
(path (expand-file-name (file-name-directory file)))
(path (file-name-as-directory (expand-file-name dir)))
(pfc (ede-directory-project-p path))
(toppath nil)
(o nil))
......@@ -920,13 +1048,11 @@ Optional ROOTRETURN will return the root project for DIR."
;; See if it's been loaded before
(setq o (object-assoc (ede-dir-to-projectfile pfc toppath) 'file
ede-projects))
(if (not o)
;; If not, get it now.
(let ((ede-constructing pfc))
(setq o (funcall (oref pfc load-type) toppath))
(when (not o)
(error "Project type error: :load-type failed to create a project"))
(ede-add-project-to-global-list o)))
;; If not open yet, load it.
(unless o
(let ((ede-constructing pfc))
(setq o (ede-auto-load-project pfc toppath))))
;; Return the found root project.
(when rootreturn (set rootreturn o))
......@@ -980,13 +1106,7 @@ Optional argument OBJ is an object to find the parent of."
(and root
(ede-find-subproject-for-directory root updir))
;; Try the all structure based search.
(ede-directory-get-open-project updir)
;; Load up the project file as a last resort.
;; Last resort since it uses file-truename, and other
;; slow features.
(and (ede-directory-project-p updir)
(ede-load-project-file
(file-name-as-directory updir))))))))))
(ede-directory-get-open-project updir))))))))
(defun ede-current-project (&optional dir)
"Return the current project file.
......@@ -1000,11 +1120,7 @@ If optional DIR is provided, get the project for DIR instead."
;; No current project.
(when (not ans)
(let* ((ldir (or dir default-directory)))
(setq ans (ede-directory-get-open-project ldir))
(or ans
;; No open project, if this dir pass project-p, then load.
(when (ede-directory-project-p ldir)
(setq ans (ede-load-project-file ldir))))))
(setq ans (ede-directory-get-open-project ldir))))
;; Return what we found.
ans))
......@@ -1059,12 +1175,13 @@ If TARGET belongs to a subproject, return that project file."
"Return the project which is the parent of TARGET.
It is recommended you track the project a different way as this function
could become slow in time."
;; @todo - use ede-object-project as a starting point.
(let ((ans nil) (projs ede-projects))
(while (and (not ans) projs)
(setq ans (ede-target-in-project-p (car projs) target)
projs (cdr projs)))
ans))
(or ede-object-project
;; If not cached, derive it from the current directory of the target.
(let ((ans nil) (projs ede-projects))
(while (and (not ans) projs)
(setq ans (ede-target-in-project-p (car projs) target)
projs (cdr projs)))
ans)))
(defmethod ede-find-target ((proj ede-project) buffer)
"Fetch the target in PROJ belonging to BUFFER or nil."
......
......@@ -58,6 +58,13 @@ associated with a single object class, based on the initilizeres used.")
:initform t
:documentation
"Non-nil if this is an option when a user creates a project.")
(safe-p :initarg :safe-p
:initform t
:documentation
"Non-nil if the project load files are \"safe\".
An unsafe project is one that loads project variables via Emacs
Lisp code. A safe project is one that loads project variables by
scanning files without loading Lisp code from them.")
)
"Class representing minimal knowledge set to run preliminary EDE functions.
When more advanced functionality is needed from a project type, that projects
......@@ -69,13 +76,15 @@ type is required and the load function used.")
:name "Make" :file 'ede/proj
:proj-file "Project.ede"
:load-type 'ede-proj-load
:class-sym 'ede-proj-project)
:class-sym 'ede-proj-project
:safe-p nil)
(ede-project-autoload "edeproject-automake"
:name "Automake" :file 'ede/proj
:proj-file "Project.ede"
:initializers '(:makefile-type Makefile.am)
:load-type 'ede-proj-load
:class-sym 'ede-proj-project)
:class-sym 'ede-proj-project
:safe-p nil)
(ede-project-autoload "automake"
:name "automake" :file 'ede/project-am
:proj-file "Makefile.am"
......@@ -84,6 +93,8 @@ type is required and the load function used.")
:new-p nil))
"List of vectors defining how to determine what type of projects exist.")
(put 'ede-project-class-files 'risky-local-variable t)
;;; EDE project-autoload methods
;;
(defmethod ede-project-root ((this ede-project-autoload))
......@@ -122,6 +133,19 @@ Return nil if the project file does not exist."
(when (and f (file-exists-p f))
f)))
(defmethod ede-auto-load-project ((this ede-project-autoload) dir)
"Load in the project associated with THIS project autoload description.
THIS project description should be valid for DIR, where the project will
be loaded."
;; Last line of defense: don't load unsafe projects.
(when (not (or (oref this :safe-p)
(ede-directory-safe-p dir)))
(error "Attempt to load an unsafe project (bug elsewhere in EDE)"))
;; Things are good - so load the project.
(let ((o (funcall (oref this load-type) dir)))
(when (not o)
(error "Project type error: :load-type failed to create a project"))
(ede-add-project-to-global-list o)))
(provide 'ede/auto)
......
......@@ -50,7 +50,8 @@
:name "Simple" :file 'ede/simple
:proj-file 'ede-simple-projectfile-for-dir
:load-type 'ede-simple-load
:class-sym 'ede-simple-project)
:class-sym 'ede-simple-project
:safe-p nil)
t)
(defcustom ede-simple-save-directory "~/.ede"
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment