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