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

   1 From 364c2da8741f0979dae497551e70b94c0e6c8636 Mon Sep 17 00:00:00 2001
   2 From: Jouni Malinen <j@w1.fi>
   3 Date: Sun, 7 Jul 2024 11:46:49 +0300
   4 Subject: [PATCH] SAE: Check for invalid Rejected Groups element length
   5  explicitly
   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 Signed-off-by: Jouni Malinen <j@w1.fi>
  12 ---
  13  src/ap/ieee802_11.c | 12 ++++++++++--
  14  1 file changed, 10 insertions(+), 2 deletions(-)
  15
  16 --- a/src/ap/ieee802_11.c
  17 +++ b/src/ap/ieee802_11.c
  18 @@ -1229,7 +1229,7 @@ static int check_sae_rejected_groups(str
  19                                      struct sae_data *sae)
  20  {
  21         const struct wpabuf *groups;
  22 -       size_t i, count;
  23 +       size_t i, count, len;
  24         const u8 *pos;
  25
  26         if (!sae->tmp)
  27 @@ -1239,7 +1239,15 @@ static int check_sae_rejected_groups(str
  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 +
  40 +       count = len / 2;
  41         for (i = 0; i < count; i++) {
  42                 int enabled;
  43                 u16 group;