From 61405e97788b1bc4e7c5be5b4ec04a73fc11bac2 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Wed, 13 May 2009 17:04:41 -0400 Subject: [PATCH] cfg80211: fix in nl80211_set_reg() There is a race on access to last_request and its alpha2 through reg_is_valid_request() and us possibly processing first another regulatory request on another CPU. We avoid this improbably race by locking with the cfg80211_mutex as we should have done in the first place. While at it add the assert on locking on reg_is_valid_request(). Cc: stable@kernel.org Signed-off-by: Luis R. Rodriguez Signed-off-by: John W. Linville --- net/wireless/nl80211.c | 5 ++++- net/wireless/reg.c | 2 ++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 66e0fb6a6420..632504060789 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -2570,6 +2570,8 @@ static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info) return -EINVAL; } + mutex_lock(&cfg80211_mutex); + if (!reg_is_valid_request(alpha2)) { r = -EINVAL; goto bad_reg; @@ -2607,13 +2609,14 @@ static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info) BUG_ON(rule_idx != num_rules); - mutex_lock(&cfg80211_mutex); r = set_regdom(rd); + mutex_unlock(&cfg80211_mutex); return r; bad_reg: + mutex_unlock(&cfg80211_mutex); kfree(rd); return r; } diff --git a/net/wireless/reg.c b/net/wireless/reg.c index 48db569d4c6b..8d176a8010ba 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -382,6 +382,8 @@ static int call_crda(const char *alpha2) /* Used by nl80211 before kmalloc'ing our regulatory domain */ bool reg_is_valid_request(const char *alpha2) { + assert_cfg80211_lock(); + if (!last_request) return false;