From a401d2bb363d942245acdd81c5b5a754011696ee Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 20 Jul 2011 00:52:16 +0200 Subject: cfg80211: fix scan crash on single-band cards commit 58389c69150e6032504dfcd3edca6b1975c8b5bc Author: Johannes Berg Date: Mon Jul 18 18:08:35 2011 +0200 cfg80211: allow userspace to control supported rates in scan made single-band cards crash since it would always access all wiphy->bands[]. Fix this and reject any attempts in the new helper ieee80211_get_ratemask() to do the same, rejecting rates configuration for unsupported bands. Reported-by: Pavel Roskin Tested-by: Pavel Roskin Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/wireless/nl80211.c | 4 +++- net/wireless/scan.c | 3 ++- net/wireless/util.c | 3 +++ 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 20aa390cf33..28d2aa109be 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -3454,7 +3454,9 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info) } for (i = 0; i < IEEE80211_NUM_BANDS; i++) - request->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1; + if (wiphy->bands[i]) + request->rates[i] = + (1 << wiphy->bands[i]->n_bitrates) - 1; if (info->attrs[NL80211_ATTR_SCAN_SUPP_RATES]) { nla_for_each_nested(attr, diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 1e7ff949d1a..2936cb80915 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -863,7 +863,8 @@ int cfg80211_wext_siwscan(struct net_device *dev, } for (i = 0; i < IEEE80211_NUM_BANDS; i++) - creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1; + if (wiphy->bands[i]) + creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1; rdev->scan_req = creq; err = rdev->ops->scan(wiphy, dev, creq); diff --git a/net/wireless/util.c b/net/wireless/util.c index a329429bfdd..be75a3a0424 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -1013,6 +1013,9 @@ int ieee80211_get_ratemask(struct ieee80211_supported_band *sband, { int i, j; + if (!sband) + return -EINVAL; + if (n_rates == 0 || n_rates > NL80211_MAX_SUPP_RATES) return -EINVAL; -- cgit v1.2.3-70-g09d2