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));
Reported-by: "freenerguo(郭大兴)" <freenerguo@xxxxxxxxxxx>
Signed-off-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>
---
Hi Kalle,
Here is the patch as Linus send it to us and security@xxxxxxxxxx. I
removed the lower bound check as that is already done in cfg80211.
Now I signed off on the patch although formally I suppose Linus should
sign it off. Putting it out there so people can respond as deemed
necessary.
Now fingers crossed whether patchwork will properly deal with the UTF-8
characters :-p
Regards,
Arend
---
drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index cd1d673..d182a00 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -4851,6 +4851,11 @@ static int brcmf_cfg80211_stop_ap(struct wiphy *wiphy, struct net_device *ndev)
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");
--
1.9.1
