Commit 24ca6289 authored by Will Deacon's avatar Will Deacon Committed by Greg Kroah-Hartman

mac80211: Reject malformed SSID elements

commit 4152561f 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: default avatarNicolas Waisman <nico@semmle.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20191004095132.15777-1-will@kernel.orgSigned-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 73c066a9
...@@ -2554,7 +2554,8 @@ struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw, ...@@ -2554,7 +2554,8 @@ struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw,
rcu_read_lock(); rcu_read_lock();
ssid = ieee80211_bss_get_ie(cbss, WLAN_EID_SSID); 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; ssid_len = 0;
else else
ssid_len = ssid[1]; ssid_len = ssid[1];
...@@ -5039,7 +5040,7 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata, ...@@ -5039,7 +5040,7 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
rcu_read_lock(); rcu_read_lock();
ssidie = ieee80211_bss_get_ie(req->bss, WLAN_EID_SSID); ssidie = ieee80211_bss_get_ie(req->bss, WLAN_EID_SSID);
if (!ssidie) { if (!ssidie || ssidie[1] > sizeof(assoc_data->ssid)) {
rcu_read_unlock(); rcu_read_unlock();
kfree(assoc_data); kfree(assoc_data);
return -EINVAL; return -EINVAL;
......
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