From 0626e86d2e1d0be63a56918371a15d98cfad19d1 Mon Sep 17 00:00:00 2001
From: mancha <mancha1@hush.com>
Date: Tue, 9 Jul 2013
Subject: Handle NULL returns from glibc 2.17+ crypt().

Starting with glibc 2.17 (eglibc 2.17), crypt() fails with EINVAL
(w/ NULL return) if the salt violates specifications. Additionally,
on FIPS-140 enabled Linux systems, DES/MD5-encrypted passwords
passed to crypt() fail with EPERM (w/ NULL return).

When using glibc's crypt(), check return value to avoid a possible
NULL pointer dereference.
---
 pwcheck/pwcheck_getpwnam.c | 3 ++-
 pwcheck/pwcheck_getspnam.c | 3 ++-
 saslauthd/auth_getpwent.c  | 3 ++-
 saslauthd/auth_shadow.c    | 7 ++-----
 4 files changed, 8 insertions(+), 8 deletions(-)

--- a/pwcheck/pwcheck_getpwnam.c
+++ b/pwcheck/pwcheck_getpwnam.c
@@ -32,6 +32,7 @@ extern char *crypt();
 char *password;
 {
     char* r;
+    char* crpt_passwd;
     struct passwd *pwd;

     pwd = getpwnam(userid);
@@ -41,7 +42,7 @@ char *password;
     else if (pwd->pw_passwd[0] == '*') {
 	r = "Account disabled";
     }
-    else if (strcmp(pwd->pw_passwd, crypt(password, pwd->pw_passwd)) != 0) {
+    else if (!(crpt_passwd = crypt(password, pwd->pw_passwd)) || strcmp(pwd->pw_passwd, (const char *)crpt_passwd) != 0) {
 	r = "Incorrect password";
     }
     else {
--- a/saslauthd/auth_getpwent.c
+++ b/saslauthd/auth_getpwent.c
@@ -70,6 +70,7 @@ auth_getpwent (
 {
     /* VARIABLES */
     struct passwd *pw;			/* pointer to passwd file entry */
+    char *crpt_passwd;			/* encrypted password */
     /* END VARIABLES */
   
     pw = getpwnam(login);
@@ -79,7 +80,7 @@ auth_getpwent (
 	RETURN("NO");
     }
 
-    if (strcmp(pw->pw_passwd, (const char *)crypt(password, pw->pw_passwd))) {
+    if (!(crpt_passwd = crypt(password, pw->pw_passwd)) || strcmp(pw->pw_passwd, (const char *)crpt_passwd)) {
 	RETURN("NO");
     }
 
--- a/saslauthd/auth_shadow.c
+++ b/saslauthd/auth_shadow.c
@@ -180,16 +180,13 @@ auth_shadow (
      * not returning any information about a login until we have validated
      * the password.
      */
-    cpw = strdup((const char *)crypt(password, sp->sp_pwdp));
-    if (strcmp(sp->sp_pwdp, cpw)) {
+    if (!(cpw = crypt(password, sp->sp_pwdp)) || strcmp(sp->sp_pwdp, (const char *)cpw)) {
 	if (flags & VERBOSE) {
 	    syslog(LOG_DEBUG, "DEBUG: auth_shadow: pw mismatch: '%s' != '%s'",
 		   sp->sp_pwdp, cpw);
 	}
-	free(cpw);
 	RETURN("NO");
     }
-    free(cpw);
 
     /*
      * The following fields will be set to -1 if:
@@ -251,7 +250,7 @@ auth_shadow (
 	RETURN("NO");
     }
   
-    if (strcmp(upw->upw_passwd, crypt(password, upw->upw_passwd)) != 0) {
+    if (!(cpw = crypt(password, upw->upw_passwd)) || (strcmp(upw->upw_passwd, (const char *)cpw) != 0)) {
 	if (flags & VERBOSE) {
 	    syslog(LOG_DEBUG, "auth_shadow: pw mismatch: %s != %s",
 		   password, upw->upw_passwd);
--- a/pwcheck/pwcheck_getspnam.c	2013-07-14 08:05:00.000000000 +0000
+++ b/pwcheck/pwcheck_getspnam.c	2013-07-14 08:06:10.958815179 +0000
@@ -32,13 +33,14 @@
 char *password;
 {
     struct spwd *pwd;
+    char *crpt_passwd;
 
     pwd = getspnam(userid);
     if (!pwd) {
 	return "Userid not found";
     }
     
-    if (strcmp(pwd->sp_pwdp, crypt(password, pwd->sp_pwdp)) != 0) {
+    if (!(crpt_passwd = crypt(password, pwd->sp_pwdp)) || strcmp(pwd->sp_pwdp, (const char *)crpt_passwd) != 0) {
 	return "Incorrect password";
     }
     else {