From: Will Deacon will@kernel.org
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: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/mac80211/mlme.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -2431,7 +2431,8 @@ struct sk_buff *ieee80211_ap_probereq_ge
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]; @@ -4669,7 +4670,7 @@ int ieee80211_mgd_assoc(struct ieee80211
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;