package/kernel/mac80211/patches/323-v4.13-0006-brcmfmac-fix-possible-buffer-overflow-in-brcmf_cfg80.patch

   1 From 8f44c9a41386729fea410e688959ddaa9d51be7c Mon Sep 17 00:00:00 2001
   2 From: Arend van Spriel <arend.vanspriel@broadcom.com>
   3 Date: Fri, 7 Jul 2017 21:09:06 +0100
   4 Subject: [PATCH] brcmfmac: fix possible buffer overflow in
   5  brcmf_cfg80211_mgmt_tx()
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 The lower level nl80211 code in cfg80211 ensures that "len" is between
  11 25 and NL80211_ATTR_FRAME (2304).  We subtract DOT11_MGMT_HDR_LEN (24) from
  12 "len" so thats's max of 2280.  However, the action_frame->data[] buffer is
  13 only BRCMF_FIL_ACTION_FRAME_SIZE (1800) bytes long so this memcpy() can
  14 overflow.
  15
  16         memcpy(action_frame->data, &buf[DOT11_MGMT_HDR_LEN],
  17                le16_to_cpu(action_frame->len));
  18
  19 Cc: stable@vger.kernel.org # 3.9.x
  20 Fixes: 18e2f61db3b70 ("brcmfmac: P2P action frame tx.")
  21 Reported-by: "freenerguo(郭大兴)" <freenerguo@tencent.com>
  22 Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
  23 Signed-off-by: David S. Miller <davem@davemloft.net>
  24 ---
  25  drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 5 +++++
  26  1 file changed, 5 insertions(+)
  27
  28 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
  29 +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
  30 @@ -4850,6 +4850,11 @@ brcmf_cfg80211_mgmt_tx(struct wiphy *wip
  31                 cfg80211_mgmt_tx_status(wdev, *cookie, buf, len, true,
  32                                         GFP_KERNEL);
  33         } else if (ieee80211_is_action(mgmt->frame_control)) {
  34 +               if (len > BRCMF_FIL_ACTION_FRAME_SIZE + DOT11_MGMT_HDR_LEN) {
  35 +                       brcmf_err("invalid action frame length\n");
  36 +                       err = -EINVAL;
  37 +                       goto exit;
  38 +               }
  39                 af_params = kzalloc(sizeof(*af_params), GFP_KERNEL);
  40                 if (af_params == NULL) {
  41                         brcmf_err("unable to allocate frame\n");