From e438768ff9b22c83a968e14b79e8c83128e8bfe4 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Tue, 5 Nov 2013 09:18:01 -0800 Subject: [PATCH] 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 Signed-off-by: Johannes Berg --- net/wireless/nl80211.c | 3 +++ net/wireless/reg.c | 2 +- net/wireless/reg.h | 1 + 3 files changed, 5 insertions(+), 1 deletion(-) 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(®_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); -- 2.20.1