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nl80211: return error for invalid center_freq in 40 MHz

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When NL80211_ATTR_WIPHY_CHANNEL_TYPE is given, nl80211 would parse the
channel definition the old way, discarding NL80211_ATTR_CENTER_FREQ1,
NL80211_ATTR_CENTER_FREQ2 etc. However, it is possible that user space
added both NL80211_ATTR_WIPHY_CHANNEL_TYPE and NL80211_ATTR_CENTER_FREQ1
or NL80211_ATTR_CENTER_FREQ2 assuming that all settings would be honored.

In such a case, validate that NL80211_ATTR_CENTER_FREQ1 and
NL80211_ATTR_CENTER_FREQ2 values match the channel configuration,
as otherwise user space would assume that the desired configuration was
applied.

For example, when trying to start ap with
NL80211_ATTR_WIPHY_CHANNEL_TYPE = NL80211_CHAN_HT40MINUS,
NL80211_ATTR_WIPHY_FREQ = 5180 and NL80211_ATTR_CENTER_FREQ1 = 5250
without this fix, the ap will start on channel 36 (center_freq1 will be
corrected to 5180).  With this fix, we will throw an error instead.

Signed-off-by: Tova Mussai <tova.mussai@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Tova Mussai 2017-08-05 11:44:38 +03:00 committed by Johannes Berg
parent a7f26d8050
commit ffa4629e0c
1 changed files with 9 additions and 0 deletions
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9
net/wireless/nl80211.c
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@ -2122,6 +2122,15 @@ static int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
case NL80211_CHAN_HT40MINUS:
cfg80211_chandef_create(chandef, chandef->chan,
chantype);
/* user input for center_freq is incorrect */
if (info->attrs[NL80211_ATTR_CENTER_FREQ1] &&
chandef->center_freq1 != nla_get_u32(
info->attrs[NL80211_ATTR_CENTER_FREQ1]))
return -EINVAL;
/* center_freq2 must be zero */
if (info->attrs[NL80211_ATTR_CENTER_FREQ2] &&
nla_get_u32(info->attrs[NL80211_ATTR_CENTER_FREQ2]))
return -EINVAL;
break;
default:
return -EINVAL;