From 15ca51e3e2a31efc275b616106244d8ec3f8f773 Mon Sep 17 00:00:00 2001
From: Denis Vlasenko
Date: Mon, 29 Oct 2007 19:25:45 +0000
Subject: appletlib.c: make it actally follow _BB_SUID_ALWAYS rules adduser:
 implement -S and code shrink / fix uid selection *: sanitize getspnam_r use

   text    data     bss     dec     hex filename
 777042     974    9676  787692   c04ec busybox_old
 776883     974    9676  787533   c044d busybox_unstripped

---
 loginutils/sulogin.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

(limited to 'loginutils/sulogin.c')

diff --git a/loginutils/sulogin.c b/loginutils/sulogin.c
index f633fbb..f1545b7 100644
--- a/loginutils/sulogin.c
+++ b/loginutils/sulogin.c
@@ -44,7 +44,6 @@ int sulogin_main(int argc, char **argv)
 	/* Using _r function to avoid pulling in static buffers */
 	char buffer[256];
 	struct spwd spw;
-	struct spwd *result;
 #endif
 
 	logmode = LOGMODE_BOTH;
@@ -83,10 +82,16 @@ int sulogin_main(int argc, char **argv)
 	}
 
 #if ENABLE_FEATURE_SHADOWPASSWDS
-	if (getspnam_r(pwd->pw_name, &spw, buffer, sizeof(buffer), &result)) {
-		goto auth_error;
+	{
+		/* getspnam_r may return 0 yet set result to NULL.
+		 * At least glibc 2.4 does this. Be extra paranoid here. */
+		struct spwd *result = NULL;
+		int r = getspnam_r(pwd->pw_name, &spw, buffer, sizeof(buffer), &result);
+		if (r || !result) {
+			goto auth_error;
+		}
+		pwd->pw_passwd = result->sp_pwdp;
 	}
-	pwd->pw_passwd = spw.sp_pwdp;
 #endif
 
 	while (1) {
-- 
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