This is a note to let you know that I've just added the patch titled brcmfmac: fix possible buffer overflow in brcmf_cfg80211_mgmt_tx() to the 4.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: brcmfmac-fix-possible-buffer-overflow-in-brcmf_cfg80211_mgmt_tx.patch and it can be found in the queue-4.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Mon Jul 17 18:46:41 CEST 2017 From: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx> Date: Fri, 7 Jul 2017 21:09:06 +0100 Subject: brcmfmac: fix possible buffer overflow in brcmf_cfg80211_mgmt_tx() From: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx> [ Upstream commit 8f44c9a41386729fea410e688959ddaa9d51be7c ] 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@xxxxxxxxxxxxxxx # 3.9.x Fixes: 18e2f61db3b70 ("brcmfmac: P2P action frame tx.") Reported-by: "freenerguo(郭大兴)" <freenerguo@xxxxxxxxxxx> Signed-off-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -4851,6 +4851,11 @@ 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"); Patches currently in stable-queue which might be from arend.vanspriel@xxxxxxxxxxxx are queue-4.12/brcmfmac-fix-possible-buffer-overflow-in-brcmf_cfg80211_mgmt_tx.patch