rt2x00: Fix panic on frame padding for rt2800 usb devices

Backtrace:
  rt2800usb_write_tx_data
  rt2x00queue_write_tx_frame
  rt2x00mac_tx
  invoke_tx_handlers
  __ieee80211_tx
  ieee80211_tx
  virt_to_head_page
  ieee80211_xmit
  ieee80211_tx_skb
  ieee80211_scan_work
  schedule
  ieee80211_scan_work
  process_one_work
  ...

It tried to expand the skb past it's end using skb_put. So I replaced it
with a call to skb_padto, which takes the issue into account.

Signed-off-by: Ismael Luceno <ismael.luceno@gmail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Ismael Luceno 2010-12-27 15:06:17 +01:00 committed by John W. Linville
parent 736e3acadc
commit 11f16aefcc

View File

@ -369,7 +369,10 @@ static void rt2800usb_write_tx_desc(struct queue_entry *entry,
static void rt2800usb_write_tx_data(struct queue_entry *entry,
struct txentry_desc *txdesc)
{
u8 padding_len;
unsigned int len;
int err;
rt2800_write_tx_data(entry, txdesc);
/*
* pad(1~3 bytes) is added after each 802.11 payload.
@ -378,9 +381,14 @@ static void rt2800usb_write_tx_data(struct queue_entry *entry,
* | TXINFO | TXWI | 802.11 header | L2 pad | payload | pad | USB end pad |
* |<------------- tx_pkt_len ------------->|
*/
rt2800_write_tx_data(entry, txdesc);
padding_len = roundup(entry->skb->len + 4, 4) - entry->skb->len;
memset(skb_put(entry->skb, padding_len), 0, padding_len);
len = roundup(entry->skb->len, 4) + 4;
err = skb_padto(entry->skb, len);
if (unlikely(err)) {
WARNING(entry->queue->rt2x00dev, "TX SKB padding error, out of memory\n");
return;
}
entry->skb->len = len;
}
/*