From: Luis R. Rodriguez Date: Sun, 31 May 2009 22:24:34 +0000 (-0400) Subject: cfg80211: fix for duplicate userspace replies X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=729e9c7663190d71fe5e29831634df80f38199c1;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git 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 Signed-off-by: Luis R. Rodriguez Signed-off-by: John W. Linville --- diff --git a/net/wireless/reg.c b/net/wireless/reg.c index f87ac1df2df5..ea4c299fbe3b 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -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); /*