From 89c4da43cbe8cfbbd949f523944343391c5302a2 Mon Sep 17 00:00:00 2001
From: Alejandro Colomar <alx@kernel.org>
Date: Thu, 7 Mar 2024 23:38:48 +0100
Subject: [PATCH] src/vipw.c: Use string literals to initialize 'Prog'

This avoids using argv[0], which is controlled by the user,
and might inject arbitrary text in stderr and the logs.

Link: <https://github.com/shadow-maint/shadow/issues/959>
Link: <https://github.com/shadow-maint/shadow/pull/960>
Cc: "Skyler Ferrante (RIT Student)" <sjf5462@rit.edu>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Karel Zak <kzak@redhat.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Cc: Christian Brauner <christian@brauner.io>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 src/vipw.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/vipw.c b/src/vipw.c
index 609ac1bfc..c30b32dee 100644
--- a/src/vipw.c
+++ b/src/vipw.c
@@ -55,7 +55,7 @@
 /*
  * Global variables
  */
-const char *Prog;
+static const char *Prog;
 
 static const char *filename, *fileeditname;
 static bool filelocked = false;
@@ -471,7 +471,9 @@ int main (int argc, char **argv)
 	bool  editshadow = false;
 	bool  do_vigr;
 
-	Prog = Basename (argv[0]);
+	do_vigr = (strcmp(Basename(argv[0]), "vigr") == 0);
+
+	Prog = do_vigr ? "vigr" : "vipw";
 	log_set_progname(Prog);
 	log_set_logfd(stderr);
 
@@ -481,9 +483,7 @@ int main (int argc, char **argv)
 
 	process_root_flag ("-R", argc, argv);
 
-	do_vigr = (strcmp(Prog, "vigr") == 0);
-
-	OPENLOG(do_vigr ? "vigr" : "vipw");
+	OPENLOG(Prog);
 
 	{
 		/*
-- 
2.47.2