[Toybox] [PATCH 1/2] login: Fix segfault if unknown username is provided

[Eli Lipsitz]

The 'login' command segfaults if the user provides an invalid username.
This happens because 'getpwnam' returns NULL, and this is stored in a
local variable. Later, after the password check fails, the pointer is
dereferenced to produce the syslog message.

This commit fixes the bug by instead using the 'username' variable in
the log message, which is never NULL.
---
 toys/other/login.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/toys/other/login.c b/toys/other/login.c
index 46fe0f67..bcca4aea 100644
--- a/toys/other/login.c
+++ b/toys/other/login.c
@@ -91,7 +91,7 @@ void login_main(void)
       if (x) break;
     }
 
-    syslog(LOG_WARNING, "invalid password for '%s' on %s %s%s", pwd->pw_name,
+    syslog(LOG_WARNING, "invalid password for '%s' on %s %s%s", username,
       ttyname(tty), hh ? "from " : "", hh ? TT.h : "");
 
     sleep(3);
-- 
2.39.1.405.gd4c25cc71f-goog