mac80211: explicitly check skb->len
ieee80211_get_hdrlen_from_skb internally checks the skb is long enough to
hold the full ieee80211_hdr, else it returns zero. Use ieee80211_hdrlen
which always returns the hdrlen and check the remaining room in the
skb explicitly when removing encryption headers or the qos control field.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index aa5a191..f5537f9 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1244,9 +1244,10 @@
struct ieee80211_key *key,
struct sk_buff *skb)
{
- int hdrlen, iv_len, mic_len;
+ unsigned int hdrlen, iv_len, mic_len;
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
- hdrlen = ieee80211_get_hdrlen_from_skb(skb);
+ hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (!key)
goto no_key;
@@ -1268,24 +1269,20 @@
goto no_key;
}
- if (skb->len >= mic_len &&
+ if (skb->len >= hdrlen + mic_len &&
!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
skb_trim(skb, skb->len - mic_len);
- if (skb->len >= iv_len && skb->len > hdrlen) {
+ if (skb->len >= hdrlen + iv_len) {
memmove(skb->data + iv_len, skb->data, hdrlen);
- skb_pull(skb, iv_len);
+ hdr = (struct ieee80211_hdr *)skb_pull(skb, iv_len);
}
no_key:
- {
- struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
- u16 fc = le16_to_cpu(hdr->frame_control);
- if ((fc & 0x8C) == 0x88) /* QoS Control Field */ {
- fc &= ~IEEE80211_STYPE_QOS_DATA;
- hdr->frame_control = cpu_to_le16(fc);
- memmove(skb->data + 2, skb->data, hdrlen - 2);
- skb_pull(skb, 2);
- }
+ if (ieee80211_is_data_qos(hdr->frame_control)) {
+ hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
+ memmove(skb->data + IEEE80211_QOS_CTL_LEN, skb->data,
+ hdrlen - IEEE80211_QOS_CTL_LEN);
+ skb_pull(skb, IEEE80211_QOS_CTL_LEN);
}
}