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 <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Luis R. Rodriguez 2009-05-13 17:04:41 -04:00 committed by John W. Linville
parent d0e18f833d
commit 61405e9778
2 changed files with 6 additions and 1 deletions

View file

@ -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;
}

View file

@ -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;