Relevant BUGIDs: 728887

Purpose of commit: bugfix

Commit summary:
---------------
Protect against segfaults in pam_start() when called with an invalid
pamh argument.

diff --git a/libpam/pam_start.c b/libpam/pam_start.c
index 0e50bb4039ffe9498a0981e06a9d7421a9246e42..7febeb8df1818eec1e4179b26de070670655bcd4 100644 (file)
--- a/libpam/pam_start.c
+++ b/libpam/pam_start.c
@@ -24,6 +24,11 @@ int pam_start (
     D(("called pam_start: [%s] [%s] [%p] [%p]"
        ,service_name, user, pam_conversation, pamh));
 
+    if (pamh == NULL) {
+       _pam_system_log(LOG_CRIT, "pam_start: invalid argument: pamh == NULL");
+       return (PAM_BUF_ERR);
+    }
+
     if ((*pamh = calloc(1, sizeof(**pamh))) == NULL) {
        _pam_system_log(LOG_CRIT, "pam_start: calloc failed for *pamh");
        return (PAM_BUF_ERR);