blob: df61f7ea714fd4e2df2d5b4de99483ffe7666817 [file] [log] [blame]
From 54af4388158fa0b403853770d444ff8c85b88837 Mon Sep 17 00:00:00 2001
From: Will Deacon <will@kernel.org>
Date: Fri, 4 Oct 2019 10:51:31 +0100
Subject: [PATCH] mac80211: Reject malformed SSID elements
commit 4152561f5da3fca92af7179dd538ea89e248f9d0 upstream.
Although this shouldn't occur in practice, it's a good idea to bounds
check the length field of the SSID element prior to using it for things
like allocations or memcpy operations.
Cc: <stable@vger.kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Reported-by: Nicolas Waisman <nico@semmle.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20191004095132.15777-1-will@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 36b60f39930b..e75f1b4b3ce3 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2628,7 +2628,8 @@ struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw,
rcu_read_lock();
ssid = ieee80211_bss_get_ie(cbss, WLAN_EID_SSID);
- if (WARN_ON_ONCE(ssid == NULL))
+ if (WARN_ONCE(!ssid || ssid[1] > IEEE80211_MAX_SSID_LEN,
+ "invalid SSID element (len=%d)", ssid ? ssid[1] : -1))
ssid_len = 0;
else
ssid_len = ssid[1];
@@ -5207,7 +5208,7 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
rcu_read_lock();
ssidie = ieee80211_bss_get_ie(req->bss, WLAN_EID_SSID);
- if (!ssidie) {
+ if (!ssidie || ssidie[1] > sizeof(assoc_data->ssid)) {
rcu_read_unlock();
kfree(assoc_data);
return -EINVAL;
--
2.7.4