git.librecmc.org Git - librecmc/librecmc.git/blob

   1 From fe76f487e28bdc61940f304f153a954cf36935ea Mon Sep 17 00:00:00 2001
   2 From: Jouni Malinen <jouni@codeaurora.org>
   3 Date: Wed, 17 Apr 2019 01:55:32 +0300
   4 Subject: [PATCH 1/3] EAP-pwd server: Fix reassembly buffer handling
   5
   6 data->inbuf allocation might fail and if that were to happen, the next
   7 fragment in the exchange could have resulted in NULL pointer
   8 dereference. Unexpected fragment with more bit might also be able to
   9 trigger this. Fix that by explicitly checking for data->inbuf to be
  10 available before using it.
  11
  12 Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
  13 ---
  14  src/eap_server/eap_server_pwd.c | 8 +++++++-
  15  1 file changed, 7 insertions(+), 1 deletion(-)
  16
  17 --- a/src/eap_server/eap_server_pwd.c
  18 +++ b/src/eap_server/eap_server_pwd.c
  19 @@ -947,6 +947,12 @@ static void eap_pwd_process(struct eap_s
  20          * the first and all intermediate fragments have the M bit set
  21          */
  22         if (EAP_PWD_GET_MORE_BIT(lm_exch) || data->in_frag_pos) {
  23 +               if (!data->inbuf) {
  24 +                       wpa_printf(MSG_DEBUG,
  25 +                                  "EAP-pwd: No buffer for reassembly");
  26 +                       eap_pwd_state(data, FAILURE);
  27 +                       return;
  28 +               }
  29                 if ((data->in_frag_pos + len) > wpabuf_size(data->inbuf)) {
  30                         wpa_printf(MSG_DEBUG, "EAP-pwd: Buffer overflow "
  31                                    "attack detected! (%d+%d > %d)",
  32 @@ -967,7 +973,7 @@ static void eap_pwd_process(struct eap_s
  33          * last fragment won't have the M bit set (but we're obviously
  34          * buffering fragments so that's how we know it's the last)
  35          */
  36 -       if (data->in_frag_pos) {
  37 +       if (data->in_frag_pos && data->inbuf) {
  38                 pos = wpabuf_head_u8(data->inbuf);
  39                 len = data->in_frag_pos;
  40                 wpa_printf(MSG_DEBUG, "EAP-pwd: Last fragment, %d bytes",