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authorJohn W. Linville <linville@tuxdriver.com>2009-05-05 15:18:26 -0400
committerJohn W. Linville <linville@tuxdriver.com>2009-05-11 15:07:01 -0400
commit621ad7c96aa138cfeab53cd4debc5a4e08b2189b (patch)
tree1759dce722d8b8798698540d1db11c2027c27ecf
parentaedec9226809ae9d1972f8f8079fc70206ee7a88 (diff)
downloadlwn-621ad7c96aa138cfeab53cd4debc5a4e08b2189b.tar.gz
lwn-621ad7c96aa138cfeab53cd4debc5a4e08b2189b.zip
mac80211: avoid NULL ptr deref when finding max_rates in PID and minstrel
"There is another problem with this piece of code. The sband will be NULL after second iteration on single band device and cause null pointer dereference. Everything is working with dual band card. Sorry, but i don't know how to explain this clearly in English. I have looked on the second patch for pid algorithm and found similar bug." Reported-by: Karol Szuster <qflon@o2.pl> Signed-off-by: John W. Linville <linville@tuxdriver.com>
-rw-r--r--net/mac80211/rc80211_minstrel.c2
-rw-r--r--net/mac80211/rc80211_pid_algo.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index 70df3dcc3cf6..d9233ec50610 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -477,7 +477,7 @@ minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
sband = hw->wiphy->bands[i];
- if (sband->n_bitrates > max_rates)
+ if (sband && sband->n_bitrates > max_rates)
max_rates = sband->n_bitrates;
}
diff --git a/net/mac80211/rc80211_pid_algo.c b/net/mac80211/rc80211_pid_algo.c
index 01d59a8e334c..8bef9a1262ff 100644
--- a/net/mac80211/rc80211_pid_algo.c
+++ b/net/mac80211/rc80211_pid_algo.c
@@ -378,7 +378,7 @@ static void *rate_control_pid_alloc(struct ieee80211_hw *hw,
for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
sband = hw->wiphy->bands[i];
- if (sband->n_bitrates > max_rates)
+ if (sband && sband->n_bitrates > max_rates)
max_rates = sband->n_bitrates;
}