package/mac80211/patches/306-pending-rt2x00-zero-out-rx_status.patch

   1 From e922d683ca8001ce9a6272d6ab12d74e72c36521 Mon Sep 17 00:00:00 2001
   2 From: Gabor Juhos <juhosg@openwrt.org>
   3 Date: Tue, 11 Dec 2012 14:15:53 +0100
   4 Subject: [PATCH v2] rt2x00: zero-out rx_status
   5
   6 In commit 'mac80211: support radiotap vendor namespace RX data'
   7 new fields were added to 'struct ieee80211_rx_status' and those
   8 fileds must be zeroed. However the rt2x00 driver stores driver
   9 specific data in the cb array of the rx skbs, so the fields
  10 might contain garbage and this can cause unexpected behaviour.
  11
  12 The rt2x00 driver from the compat-wireless-2012-12-01
  13 tarball caused the following warning:
  14
  15   WARNING: at
  16   /devel/ramips/build_dir/target-mipsel_r2_uClibc-0.9.33.2/linux-ramips_rt305x/
  17   compat-wireless-2012-12-01/net/mac80211/rx.c:115 ieee80211_rx_irqsafe+0x274/0xbcc
  18   [mac80211]()
  19   Modules linked in: dwc_otg ledtrig_usbdev nf_nat_irc
  20   nf_nat_ftp nf_conntrack_irc nf_conntrack_ftp ipt_MASQUERADE
  21   iptable_nat nf_nat pppoe xt_conntrack xt_CT xt_NOTRACK iptable_raw
  22   xt_state nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack pppox
  23   ipt_REJECT xt_TCPMSS xt_comment xt_multiport xt_mac xt_limit
  24   iptable_mangle iptable_filter ip_tables xt_tcpudp x_tables ppp_async
  25   ppp_generic slhc rt2800pci(O) rt2800lib(O) rt2x00soc(O) rt2x00pci(O)
  26   rt2x00lib(O) mac80211(O) usbcore usb_common nls_base crc_itu_t
  27   crc_ccitt eeprom_93cx6 cfg80211(O) compat(O) arc4 aes_generic
  28   crypto_blkcipher cryptomgr aead crypto_hash crypto_algapi leds_gpio
  29   button_hotplug(O) gpio_keys_polled input_polldev input_core
  30   Call Trace:
  31   [<801e96b4>] dump_stack+0x8/0x34
  32   [<80010a9c>] warn_slowpath_common+0x78/0xa4
  33   [<80010ae0>] warn_slowpath_null+0x18/0x24
  34   [<80a9710c>] ieee80211_rx_irqsafe+0x274/0xbcc [mac80211]
  35
  36 The patch ensures that each field gets initialized with
  37 zeroes.
  38
  39 Cc: <users@rt2x00.serialmonkey.com>
  40 Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
  41 ---
  42 v2:
  43   - update the commit message and add a comment to the code
  44   - drop the ath5k and p54 patches
  45 ---
  46  drivers/net/wireless/rt2x00/rt2x00dev.c |    8 ++++++++
  47  1 file changed, 8 insertions(+)
  48
  49 --- a/drivers/net/wireless/rt2x00/rt2x00dev.c
  50 +++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
  51 @@ -685,6 +685,14 @@ void rt2x00lib_rxdone(struct queue_entry
  52          * to mac80211.
  53          */
  54         rx_status = IEEE80211_SKB_RXCB(entry->skb);
  55 +
  56 +       /* Ensure that all fields of rx_status are initialized
  57 +        * properly. The skb->cb array was used for driver
  58 +        * specific informations, so rx_status might contain
  59 +        * garbage.
  60 +        */
  61 +       memset(rx_status, 0, sizeof(*rx_status));
  62 +
  63         rx_status->mactime = rxdesc.timestamp;
  64         rx_status->band = rt2x00dev->curr_band;
  65         rx_status->freq = rt2x00dev->curr_freq;