From 275f8cb025b32be82b2f6bb35dc15948892c5edd Mon Sep 17 00:00:00 2001 From: Tim Tianyang Chen Date: Thu, 28 Sep 2017 14:11:57 -0700 Subject: [PATCH] brcmfmac: fix possible buffer overflow in brcmf_cfg80211_mgmt_tx() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 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 (cherry picked from commit 8f44c9a41386729fea410e688959ddaa9d51be7c) Orabug: 26540118 CVE: CVE-2017-7541 Signed-off-by: Tim Tianyang Chen Reviewed-by: Kirtikar Kashyap cfg80211.c is in a different directory. Conflicts: drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c --- drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c index 8a15ebbce4a3..c304b66af5c6 100644 --- a/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c @@ -4384,6 +4384,11 @@ brcmf_cfg80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev, 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"); -- 2.50.1