s3: smbpasswd - fix crashes on invalid input.

get_pass can return NULL on error. Ensure that
this is always the case and fix all callers to cope
(some already did).

Reported by Joonas Kuorilehto <joneskoo@codenomicon.com>

BUG: https://bugzilla.samba.org/show_bug.cgi?id=10320

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Mon Dec 16 15:17:58 CET 2013 on sn-devel-104

diff --git a/source3/utils/net.c b/source3/utils/net.c
index 34736416302e708ad89f8e0aaa28d0466d338656..1308d9492e4f0e27233f530209ef5199387e9967 100644 (file)
--- a/source3/utils/net.c
+++ b/source3/utils/net.c
@@ -105,6 +105,11 @@ static int net_changesecretpw(struct net_context *c, int argc,
                }
 
                trust_pw = get_pass(_("Enter machine password: "), c->opt_stdin);
+               if (trust_pw == NULL) {
+                           d_fprintf(stderr,
+                                     _("Error in reading machine password\n"));
+                           return 1;
+               }
 
                if (!secrets_store_machine_password(trust_pw, lp_workgroup(), sec_channel_type)) {
                            d_fprintf(stderr,

diff --git a/source3/utils/passwd_util.c b/source3/utils/passwd_util.c
index 5716c17a3aaecc0f5052bfe6d873b1a5703cf3d5..4884d63bf10984c271de794a90e90db2d0a4f396 100644 (file)
--- a/source3/utils/passwd_util.c
+++ b/source3/utils/passwd_util.c
@@ -42,11 +42,12 @@ char *stdin_new_passwd( void)
         * the newline that ends the password, then replace the newline with
         * a null terminator.
         */
-       if ( fgets(new_pw, sizeof(new_pw), stdin) != NULL) {
-               if ((len = strlen(new_pw)) > 0) {
-                       if(new_pw[len-1] == '\n')
-                               new_pw[len - 1] = 0;
-               }
+       if ( fgets(new_pw, sizeof(new_pw), stdin) == NULL) {
+               return NULL;
+       }
+       if ((len = strlen(new_pw)) > 0) {
+               if(new_pw[len-1] == '\n')
+                       new_pw[len - 1] = 0;
        }
        return(new_pw);
 }
@@ -64,6 +65,9 @@ char *get_pass( const char *prompt, bool stdin_get)
 
        if (stdin_get) {
                p = stdin_new_passwd();
+               if (p == NULL) {
+                       return NULL;
+               }
        } else {
                rc = samba_getpass(prompt, pwd, sizeof(pwd), false, false);
                if (rc < 0) {

diff --git a/source3/utils/smbpasswd.c b/source3/utils/smbpasswd.c
index d93261eade342efb7505e3c6ec25863bdbf69f42..67780ff7cd6b6ff55fbd0a8dce2717367ff00d0f 100644 (file)
--- a/source3/utils/smbpasswd.c
+++ b/source3/utils/smbpasswd.c
@@ -217,11 +217,17 @@ static char *prompt_for_new_password(bool stdin_get)
        ZERO_ARRAY(new_pw);
 
        p = get_pass("New SMB password:", stdin_get);
+       if (p == NULL) {
+               return NULL;
+       }
 
        fstrcpy(new_pw, p);
        SAFE_FREE(p);
 
        p = get_pass("Retype new SMB password:", stdin_get);
+       if (p == NULL) {
+               return NULL;
+       }
 
        if (strcmp(p, new_pw)) {
                fprintf(stderr, "Mismatch - password unchanged.\n");
@@ -311,6 +317,10 @@ static int process_root(int local_flags)
                printf("Setting stored password for \"%s\" in secrets.tdb\n", ldap_admin_dn);
                if ( ! *ldap_secret ) {
                        new_passwd = prompt_for_new_password(stdin_passwd_get);
+                       if (new_passwd == NULL) {
+                               fprintf(stderr, "Failed to read new password!\n");
+                               exit(1);
+                       }
                        fstrcpy(ldap_secret, new_passwd);
                }
                if (!store_ldap_admin_pw(ldap_secret)) {
@@ -538,6 +548,10 @@ static int process_nonroot(int local_flags)
 
        if (remote_machine != NULL) {
                old_pw = get_pass("Old SMB password:",stdin_passwd_get);
+               if (old_pw == NULL) {
+                       fprintf(stderr, "Unable to get old password.\n");
+                       exit(1);
+               }
        }
 
        if (!new_passwd) {