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authorLuis R. Rodriguez <mcgrof@do-not-panic.com>2013-11-05 09:18:01 -0800
committerJohannes Berg <johannes.berg@intel.com>2013-11-25 20:51:02 +0100
commite438768ff9b22c83a968e14b79e8c83128e8bfe4 (patch)
tree956366ad035f64af8965c3a737eaa74598d1e1b6
parentcc493e4f5296f4da111f25ea4a216bb77270ccc6 (diff)
downloadlinux-e438768ff9b22c83a968e14b79e8c83128e8bfe4.tar.gz
cfg80211: check regulatory request alpha2 early
Currently nl80211 allows userspace to send the kernel
a bogus regulatory domain with at most 32 rules set
and it won't reject it until after its allocated
memory. Let's be smart about it and take advantage
that the last_request is now available under RTNL
and check if the alpha2 matches an expected request
and reject any bogus userspace requests prior to
hitting the memory allocator.

Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
-rw-r--r--net/wireless/nl80211.c3
-rw-r--r--net/wireless/reg.c2
-rw-r--r--net/wireless/reg.h1
3 files changed, 5 insertions, 1 deletions
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 04fa8bb1b4bb..7b73132910b7 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5100,6 +5100,9 @@ static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info)
 			return -EINVAL;
 	}
 
+	if (!reg_is_valid_request(alpha2))
+		return -EINVAL;
+
 	size_of_regd = sizeof(struct ieee80211_regdomain) +
 		       num_rules * sizeof(struct ieee80211_reg_rule);
 
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index b4b16871a56e..d8f047aadd49 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -450,7 +450,7 @@ static int call_crda(const char *alpha2)
 	return kobject_uevent(&reg_pdev->dev.kobj, KOBJ_CHANGE);
 }
 
-static bool reg_is_valid_request(const char *alpha2)
+bool reg_is_valid_request(const char *alpha2)
 {
 	struct regulatory_request *lr = get_last_request();
 
diff --git a/net/wireless/reg.h b/net/wireless/reg.h
index 9677e3c13da9..b4076babaf47 100644
--- a/net/wireless/reg.h
+++ b/net/wireless/reg.h
@@ -18,6 +18,7 @@
 
 extern const struct ieee80211_regdomain __rcu *cfg80211_regdomain;
 
+bool reg_is_valid_request(const char *alpha2);
 bool is_world_regdom(const char *alpha2);
 bool reg_supported_dfs_region(u8 dfs_region);