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mac80211: explicitly check skb->len

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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>
This commit is contained in:
Harvey Harrison 2008-07-15 18:44:05 -07:00 committed by John W. Linville
parent 798ee9850e
commit 62bf1d762e
1 changed files with 11 additions and 14 deletions
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25
net/mac80211/main.c
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@ -1244,9 +1244,10 @@ static void ieee80211_remove_tx_extra(struct ieee80211_local *local,
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 @@ static void ieee80211_remove_tx_extra(struct ieee80211_local *local,
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);
}
}