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authorJohannes Berg <johannes.berg@intel.com>2011-11-08 12:28:33 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2011-11-26 09:09:54 -0800
commit492d7eff2def54c6e5521ee82764ca22025e7030 (patch)
tree2d1ae2f73e8f59b36462caa33086c48d02fe7b04 /net/mac80211
parent11885cd854b27c1dcf35ab44d4899e8d20e08290 (diff)
mac80211: fix NULL dereference in radiotap code
commit f8d1ccf15568268c76f913b45ecdd33134387f1a upstream. When receiving failed PLCP frames is enabled, there won't be a rate pointer when we add the radiotap header and thus the kernel will crash. Fix this by not assuming the rate pointer is always valid. It's still always valid for frames that have good PLCP though, and that is checked & enforced. This was broken by my commit fc88518916793af8ad6a02e05ff254d95c36d875 Author: Johannes Berg <johannes.berg@intel.com> Date: Fri Jul 30 13:23:12 2010 +0200 mac80211: don't check rates on PLCP error frames where I removed the check in this case but didn't take into account that the rate info would be used. Reported-by: Xiaokang Qin <xiaokang.qin@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'net/mac80211')
-rw-r--r--net/mac80211/rx.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 7fa8c6be7bf0..378bd67334ba 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -140,8 +140,9 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
pos++;
/* IEEE80211_RADIOTAP_RATE */
- if (status->flag & RX_FLAG_HT) {
+ if (!rate || status->flag & RX_FLAG_HT) {
/*
+ * Without rate information don't add it. If we have,
* MCS information is a separate field in radiotap,
* added below. The byte here is needed as padding
* for the channel though, so initialise it to 0.
@@ -162,12 +163,14 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
else if (status->flag & RX_FLAG_HT)
put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
pos);
- else if (rate->flags & IEEE80211_RATE_ERP_G)
+ else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
pos);
- else
+ else if (rate)
put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
pos);
+ else
+ put_unaligned_le16(IEEE80211_CHAN_2GHZ, pos);
pos += 2;
/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */