From 7321ceaf69a7028a04056e548d861b291634c2d0 Mon Sep 17 00:00:00 2001
From: Samanta Navarro <ferivoz@riseup.net>
Date: Thu, 18 May 2023 11:58:19 +0000
Subject: [PATCH] chsh: Verify that login shell path is absolute

The getusershell implementation of musl returns every line within the
/etc/shells file, which even includes comments. Only consider absolute
paths for login shells.

Signed-off-by: Samanta Navarro <ferivoz@riseup.net>
---
 src/chsh.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/chsh.c b/src/chsh.c
index 639ff630..d6eca6e3 100644
--- a/src/chsh.c
+++ b/src/chsh.c
@@ -574,7 +574,8 @@ int main (int argc, char **argv)
 		fail_exit (1);
 	}
 	if (   !amroot
-	    && (   is_restricted_shell (loginsh)
+	    && (   loginsh[0] != '/'
+	        || is_restricted_shell (loginsh)
 	        || (access (loginsh, X_OK) != 0))) {
 		fprintf (stderr, _("%s: %s is an invalid shell\n"), Prog, loginsh);
 		fail_exit (1);