Subject: bug#61709: [PATCH] Security hardening: safely invoke `shell-command*' function.

From: Xi Lu <[email-masked]>
Date: Wed, 22 Feb 2023 22:35:54 +0800

* lisp/filesets.el:
(filesets-select-command, filesets-which-command,
filesets-spawn-external-viewer, filesets-run-cmd): Add `shell-quote-argument'
---
 lisp/filesets.el | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/lisp/filesets.el b/lisp/filesets.el
index 1b7e6ffa81f..96ac11bb40b 100644
--- a/lisp/filesets.el
+++ b/lisp/filesets.el
@@ -165,14 +165,15 @@ filesets-select-command
   "Select one command from CMD-LIST -- a string with space separated names."
   (let ((this (shell-command-to-string
 	       (format "which --skip-alias %s 2> %s | head -n 1"
-		       cmd-list null-device))))
+		       (shell-quote-argument cmd-list)
+                       (shell-quote-argument null-device)))))
     (if (equal this "")
 	nil
       (file-name-nondirectory (substring this 0 (- (length this) 1))))))
 
 (defun filesets-which-command (cmd)
   "Call \"which CMD\"."
-  (shell-command-to-string (format "which %s" cmd)))
+  (shell-command-to-string (format "which %s" (shell-quote-argument cmd))))
 
 (defun filesets-which-command-p (cmd)
   "Call \"which CMD\" and return non-nil if the command was found."
@@ -1264,9 +1265,11 @@ filesets-spawn-external-viewer
 		  (funcall vwr file)
 		  nil)
 		 (co-flag
-		  (shell-command-to-string (format "%s %s" vwr args)))
+		  (shell-command-to-string (shell-quote-argument
+                                            (format "%s %s" vwr args))))
 		 (t
-		  (shell-command (format "%s %s&" vwr args))
+		  (shell-command (shell-quote-argument
+                                  (format "%s %s&" vwr args)))
 		  nil))))
 	  (if co-flag
 	      (progn
@@ -1578,7 +1581,7 @@ filesets-run-cmd
 				   " "))
 				 (cmd (concat fn " " args)))
 			    (filesets-cmd-show-result
-			     cmd (shell-command-to-string cmd))))
+			     cmd (shell-command-to-string (shell-quote-argument cmd)))))
 			 ((symbolp fn)
 			  (apply fn
 			         (mapcan (lambda (this)
-- 
2.39.2