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cfg80211: fix for duplicate userspace replies 

This fixes an incorrect assumption (BUG_ON) made in
cfg80211 when handling country IE regulatory requests.
The assumption was that we won't try to call_crda()
twice for the same event and therefore we will not
recieve two replies through nl80211 for the regulatory
request. As it turns out it is true we don't call_crda()
twice for the same event, however, kobject_uevent_env()
*might* send the udev event twice and/or userspace can
simply process the udev event twice. We remove the BUG_ON()
and simply ignore the duplicate request.

For details refer to this thread:

http://marc.info/?l=linux-wireless&m=124149987921337&w=2

Cc: stable@kernel.org
Reported-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Luis R. Rodriguez 2009-05-31 18:24:34 -04:00 committed by John W. Linville
parent 3b8bcfd5d3
commit 729e9c7663
1 changed files with 7 additions and 1 deletions
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8
net/wireless/reg.c
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@ -2171,7 +2171,13 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
* the country IE rd with what CRDA believes that country should have
*/
BUG_ON(!country_ie_regdomain);
/*
* Userspace could have sent two replies with only
* one kernel request. By the second reply we would have
* already processed and consumed the country_ie_regdomain.
*/
if (!country_ie_regdomain)
return -EALREADY;
BUG_ON(rd == country_ie_regdomain);
/*