cfg80211: validate scan channels
Currently it is possible to request a scan on only
disabled channels, which could be problematic for
some drivers. Reject such scans, and also ignore
disabled channels that are given. This resuls in
the scan begin/end event only including channels
that are actually used.
This makes the mac80211 check for disabled channels
superfluous. At the same time, remove the no-IBSS
check from mac80211 -- nothing says that we should
not find any networks on channels that cannot be
used for an IBSS, even when operating in IBSS mode.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f483941..8ed62b6 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2988,7 +2988,6 @@
goto out;
}
- request->n_channels = n_channels;
if (n_ssids)
request->ssids = (void *)&request->channels[n_channels];
request->n_ssids = n_ssids;
@@ -2999,32 +2998,53 @@
request->ie = (void *)(request->channels + n_channels);
}
+ i = 0;
if (info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]) {
/* user specified, bail out if channel not found */
- request->n_channels = n_channels;
- i = 0;
nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_FREQUENCIES], tmp) {
- request->channels[i] = ieee80211_get_channel(wiphy, nla_get_u32(attr));
- if (!request->channels[i]) {
+ struct ieee80211_channel *chan;
+
+ chan = ieee80211_get_channel(wiphy, nla_get_u32(attr));
+
+ if (!chan) {
err = -EINVAL;
goto out_free;
}
+
+ /* ignore disabled channels */
+ if (chan->flags & IEEE80211_CHAN_DISABLED)
+ continue;
+
+ request->channels[i] = chan;
i++;
}
} else {
/* all channels */
- i = 0;
for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
int j;
if (!wiphy->bands[band])
continue;
for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
- request->channels[i] = &wiphy->bands[band]->channels[j];
+ struct ieee80211_channel *chan;
+
+ chan = &wiphy->bands[band]->channels[j];
+
+ if (chan->flags & IEEE80211_CHAN_DISABLED)
+ continue;
+
+ request->channels[i] = chan;
i++;
}
}
}
+ if (!i) {
+ err = -EINVAL;
+ goto out_free;
+ }
+
+ request->n_channels = i;
+
i = 0;
if (info->attrs[NL80211_ATTR_SCAN_SSIDS]) {
nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_SSIDS], tmp) {
