emacs: patch CVE-2024-39331

Details: https://nvd.nist.gov/vuln/detail/CVE-2024-39331

Pick the patch that's mentioned in thee details.

Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>

2 files changed, 72 insertions, 0 deletions

diff --git a/meta-oe/recipes-support/emacs/emacs_29.1.bb b/meta-oe/recipes-support/emacs/emacs_29.1.bb
index abc99d3e08..23388f309b 100644
--- a/meta-oe/recipes-support/emacs/emacs_29.1.bb
+++ b/meta-oe/recipes-support/emacs/emacs_29.1.bb
@@ -9,6 +9,7 @@ SRC_URI = "https://ftp.gnu.org/pub/gnu/emacs/emacs-${PV}.tar.xz \
            file://0001-lisp-gnus-mm-view.el-mm-display-inline-fontify-Mark-.patch \
            file://0001-org-latex-preview-Add-protection-when-untrusted-cont.patch \
            file://0001-org-file-contents-Consider-all-remote-files-unsafe.patch \
+           file://0001-org-link-expand-abbrev-Do-not-evaluate-arbitrary-uns.patch \
           "
 SRC_URI:append:class-target = " \
     file://use-emacs-native-tools-for-cross-compiling.patch \
diff --git a/meta-oe/recipes-support/emacs/files/0001-org-link-expand-abbrev-Do-not-evaluate-arbitrary-uns.patch b/meta-oe/recipes-support/emacs/files/0001-org-link-expand-abbrev-Do-not-evaluate-arbitrary-uns.patch
new file mode 100644
index 0000000000..88fdaaf22d
--- /dev/null
+++ b/meta-oe/recipes-support/emacs/files/0001-org-link-expand-abbrev-Do-not-evaluate-arbitrary-uns.patch
@@ -0,0 +1,71 @@
+From 8b8866eb94c7b7140ba94eb2b4e6ead14c0d986d Mon Sep 17 00:00:00 2001
+From: Ihor Radchenko <yantar92@posteo.net>
+Date: Fri, 21 Jun 2024 15:45:25 +0200
+Subject: [PATCH] org-link-expand-abbrev: Do not evaluate arbitrary unsafe
+ Elisp code
+
+* lisp/org/ol.el (org-link-expand-abbrev): Refuse expanding %(...)
+link abbrevs that specify unsafe function.  Instead, display a
+warning, and do not expand the abbrev.  Clear all the text properties
+from the returned link, to avoid any potential vulnerabilities caused
+by properties that may contain arbitrary Elisp.
+
+CVE: CVE-2024-39331
+Upstream-Status: Backport [https://cgit.git.savannah.gnu.org/cgit/emacs.git/commit/?id=c645e1d8205f0f0663ec4a2d27575b238c646c7c]
+
+Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
+---
+ lisp/org/ol.el | 40 +++++++++++++++++++++++++++++-----------
+ 1 file changed, 29 insertions(+), 11 deletions(-)
+
+diff --git a/lisp/org/ol.el b/lisp/org/ol.el
+index 9ad191c..c15128f 100644
+--- a/lisp/org/ol.el
++++ b/lisp/org/ol.el
+@@ -1063,17 +1063,35 @@ Abbreviations are defined in `org-link-abbrev-alist'."
+       (if (not as)
+          link
+        (setq rpl (cdr as))
+-       (cond
+-        ((symbolp rpl) (funcall rpl tag))
+-        ((string-match "%(\\([^)]+\\))" rpl)
+-         (replace-match
+-          (save-match-data
+-            (funcall (intern-soft (match-string 1 rpl)) tag))
+-          t t rpl))
+-        ((string-match "%s" rpl) (replace-match (or tag "") t t rpl))
+-        ((string-match "%h" rpl)
+-         (replace-match (url-hexify-string (or tag "")) t t rpl))
+-        (t (concat rpl tag)))))))
++        ;; Drop any potentially dangerous text properties like
++        ;; `modification-hooks' that may be used as an attack vector.
++        (substring-no-properties
++        (cond
++         ((symbolp rpl) (funcall rpl tag))
++         ((string-match "%(\\([^)]+\\))" rpl)
++           (let ((rpl-fun-symbol (intern-soft (match-string 1 rpl))))
++             ;; Using `unsafep-function' is not quite enough because
++             ;; Emacs considers functions like `genenv' safe, while
++             ;; they can potentially be used to expose private system
++             ;; data to attacker if abbreviated link is clicked.
++             (if (or (eq t (get rpl-fun-symbol 'org-link-abbrev-safe))
++                     (eq t (get rpl-fun-symbol 'pure)))
++                 (replace-match
++                 (save-match-data
++                   (funcall (intern-soft (match-string 1 rpl)) tag))
++                 t t rpl)
++               (org-display-warning
++                (format "Disabling unsafe link abbrev: %s
++You may mark function safe via (put '%s 'org-link-abbrev-safe t)"
++                        rpl (match-string 1 rpl)))
++               (setq org-link-abbrev-alist-local (delete as org-link-abbrev-alist-local)
++                     org-link-abbrev-alist (delete as org-link-abbrev-alist))
++               link
++              )))
++         ((string-match "%s" rpl) (replace-match (or tag "") t t rpl))
++         ((string-match "%h" rpl)
++          (replace-match (url-hexify-string (or tag "")) t t rpl))
++         (t (concat rpl tag))))))))
+ 
+ (defun org-link-open (link &optional arg)
+   "Open a link object LINK.