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>
This commit is contained in:
John W. Linville 2009-05-05 15:18:26 -04:00
parent aedec92268
commit 621ad7c96a
2 changed files with 2 additions and 2 deletions

View File

@ -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;
}

View File

@ -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;
}