NSS: Validate input string lengths

Also fixes a return value bug where we were returning errno error
codes instead of nss_status codes.

Fixes https://fedorahosted.org/sssd/ticket/1135

4 files changed, 32 insertions, 9 deletions

diff --git a/src/sss_client/nss_group.c b/src/sss_client/nss_group.c
index 9e308c92..f5e715c8 100644
--- a/src/sss_client/nss_group.c
+++ b/src/sss_client/nss_group.c
@@ -254,14 +254,23 @@ enum nss_status _nss_sss_getgrnam_r(const char *name, struct group *result,
     struct sss_cli_req_data rd;
     struct sss_nss_gr_rep grrep;
     uint8_t *repbuf;
-    size_t replen, len;
+    size_t replen, len, name_len;
     enum nss_status nret;
     int ret;
 
     /* Caught once glibc passing in buffer == 0x0 */
-    if (!buffer || !buflen) return ERANGE;
+    if (!buffer || !buflen) {
+        *errnop = ERANGE;
+        return NSS_STATUS_TRYAGAIN;
+    }
+
+    ret = sss_strnlen(name, SSS_NAME_MAX, &name_len);
+    if (ret != 0) {
+        *errnop = EINVAL;
+        return NSS_STATUS_NOTFOUND;
+    }
 
-    rd.len = strlen(name) + 1;
+    rd.len = name_len + 1;
     rd.data = name;
 
     sss_nss_lock();
diff --git a/src/sss_client/nss_netgroup.c b/src/sss_client/nss_netgroup.c
index 2d1acc5d..f63b1135 100644
--- a/src/sss_client/nss_netgroup.c
+++ b/src/sss_client/nss_netgroup.c
@@ -33,8 +33,6 @@
 #include "sss_cli.h"
 #include "nss_compat.h"
 
-#define MAX_NETGR_NAME_LENGTH 2048
-
 #define CLEAR_NETGRENT_DATA(netgrent) do { \
         free(netgrent->data); \
         netgrent->data = NULL; \
@@ -201,7 +199,7 @@ enum nss_status _nss_sss_setnetgrent(const char *netgroup,
     /* make sure we do not have leftovers, and release memory */
     CLEAR_NETGRENT_DATA(result);
 
-    ret = sss_strnlen(netgroup, MAX_NETGR_NAME_LENGTH, &name_len);
+    ret = sss_strnlen(netgroup, SSS_NAME_MAX, &name_len);
     if (ret != 0) {
         nret = NSS_STATUS_NOTFOUND;
         goto out;
diff --git a/src/sss_client/nss_passwd.c b/src/sss_client/nss_passwd.c
index 31b9a794..15de5972 100644
--- a/src/sss_client/nss_passwd.c
+++ b/src/sss_client/nss_passwd.c
@@ -179,14 +179,23 @@ enum nss_status _nss_sss_getpwnam_r(const char *name, struct passwd *result,
     struct sss_cli_req_data rd;
     struct sss_nss_pw_rep pwrep;
     uint8_t *repbuf;
-    size_t replen, len;
+    size_t replen, len, name_len;
     enum nss_status nret;
     int ret;
 
     /* Caught once glibc passing in buffer == 0x0 */
-    if (!buffer || !buflen) return ERANGE;
+    if (!buffer || !buflen) {
+        *errnop = ERANGE;
+        return NSS_STATUS_TRYAGAIN;
+    }
+
+    ret = sss_strnlen(name, SSS_NAME_MAX, &name_len);
+    if (ret != 0) {
+        *errnop = EINVAL;
+        return NSS_STATUS_NOTFOUND;
+    }
 
-    rd.len = strlen(name) + 1;
+    rd.len = name_len + 1;
     rd.data = name;
 
     sss_nss_lock();
diff --git a/src/sss_client/sss_cli.h b/src/sss_client/sss_cli.h
index f9bbda98..dc15ac13 100644
--- a/src/sss_client/sss_cli.h
+++ b/src/sss_client/sss_cli.h
@@ -29,6 +29,7 @@
 #include <pwd.h>
 #include <grp.h>
 #include <string.h>
+#include <limits.h>
 
 #ifndef HAVE_ERRNO_T
 #define HAVE_ERRNO_T
@@ -39,6 +40,12 @@ typedef int errno_t;
 #define SSS_PAM_PROTOCOL_VERSION 3
 #define SSS_SUDO_PROTOCOL_VERSION 0
 
+#ifdef LOGIN_NAME_MAX
+#define SSS_NAME_MAX LOGIN_NAME_MAX
+#else
+#define SSS_NAME_MAX 256
+#endif
+
 /**
  * @defgroup sss_cli_command SSS client commands
  * @{