git.openwrt.org Git - openwrt/staging/xback.git/blob

   1 From 593a7c2f8c93edd6b552f2d42e28164464b4e6ff Mon Sep 17 00:00:00 2001
   2 From: Jouni Malinen <j@w1.fi>
   3 Date: Tue, 9 Jul 2024 23:33:38 +0300
   4 Subject: [PATCH] SAE: Check for invalid Rejected Groups element length
   5  explicitly on STA
   6
   7 Instead of practically ignoring an odd octet at the end of the element,
   8 check for such invalid case explicitly. This is needed to avoid a
   9 potential group downgrade attack.
  10
  11 Fixes: 444d76f74f65 ("SAE: Check that peer's rejected groups are not enabled")
  12 Signed-off-by: Jouni Malinen <j@w1.fi>
  13 ---
  14  wpa_supplicant/sme.c | 11 +++++++++--
  15  1 file changed, 9 insertions(+), 2 deletions(-)
  16
  17 --- a/wpa_supplicant/sme.c
  18 +++ b/wpa_supplicant/sme.c
  19 @@ -1561,14 +1561,21 @@ static int sme_sae_is_group_enabled(stru
  20  static int sme_check_sae_rejected_groups(struct wpa_supplicant *wpa_s,
  21                                          const struct wpabuf *groups)
  22  {
  23 -       size_t i, count;
  24 +       size_t i, count, len;
  25         const u8 *pos;
  26
  27         if (!groups)
  28                 return 0;
  29
  30         pos = wpabuf_head(groups);
  31 -       count = wpabuf_len(groups) / 2;
  32 +       len = wpabuf_len(groups);
  33 +       if (len & 1) {
  34 +               wpa_printf(MSG_DEBUG,
  35 +                          "SAE: Invalid length of the Rejected Groups element payload: %zu",
  36 +                          len);
  37 +               return 1;
  38 +       }
  39 +       count = len / 2;
  40         for (i = 0; i < count; i++) {
  41                 int enabled;
  42                 u16 group;