[linux-pam] Make pam_pwhistory and pam_unix tolerant of corrupted opasswd file.

[Tomáš Mráz]

commit d65f138fbc784911399e5afe66c9661e0136b43d
Author: Tomas Mraz <tmraz(a)fedoraproject.org&gt;
Date:   Mon Jul 21 16:31:38 2014 +0200

    Make pam_pwhistory and pam_unix tolerant of corrupted opasswd file.
    
    * modules/pam_pwhistory/opasswd.c (parse_entry): Test for missing fields
    in opasswd entry and return error.
    * modules/pam_unix/passverify.c (save_old_password): Test for missing fields
    in opasswd entry and skip it.

 modules/pam_pwhistory/opasswd.c |    7 ++++++-
 modules/pam_unix/passverify.c   |   14 +++++++++++++-
 2 files changed, 19 insertions(+), 2 deletions(-)
---
diff --git a/modules/pam_pwhistory/opasswd.c b/modules/pam_pwhistory/opasswd.c
index 836d713..e6cf346 100644
--- a/modules/pam_pwhistory/opasswd.c
+++ b/modules/pam_pwhistory/opasswd.c
@@ -82,10 +82,15 @@ parse_entry (char *line, opwd *data)
 {
   const char delimiters[] = ":";
   char *endptr;
+  char *count;
 
   data->user = strsep (&line, delimiters);
   data->uid = strsep (&line, delimiters);
-  data->count = strtol (strsep (&line, delimiters), &endptr, 10);
+  count = strsep (&line, delimiters);
+  if (count == NULL)
+      return 1;
+
+  data->count = strtol (count, &endptr, 10);
   if (endptr != NULL && *endptr != '\0')
       return 1;
 
diff --git a/modules/pam_unix/passverify.c b/modules/pam_unix/passverify.c
index 4840bb2..7f7bc49 100644
--- a/modules/pam_unix/passverify.c
+++ b/modules/pam_unix/passverify.c
@@ -639,11 +639,23 @@ save_old_password(pam_handle_t *pamh, const char *forwho, const char
*oldpass,
 		continue;
 	    buf[strlen(buf) - 1] = '\0';
 	    s_luser = strtok_r(buf, ":", &sptr);
+	    if (s_luser == NULL) {
+		found = 0;
+		continue;
+	    }
 	    s_uid = strtok_r(NULL, ":", &sptr);
+	    if (s_uid == NULL) {
+		found = 0;
+		continue;
+	    }
 	    s_npas = strtok_r(NULL, ":", &sptr);
+	    if (s_npas == NULL) {
+		found = 0;
+		continue;
+	    }
 	    s_pas = strtok_r(NULL, ":", &sptr);
 	    npas = strtol(s_npas, NULL, 10) + 1;
-	    while (npas > howmany) {
+	    while (npas > howmany && s_pas != NULL) {
 		s_pas = strpbrk(s_pas, ",");
 		if (s_pas != NULL)
 		    s_pas++;