UBUNTU: SAUCE: libertas: Fix two buffer overflows at parsing bss descriptor

add_ie_rates() copys rates without checking the length
in bss descriptor from remote AP.when victim connects to
remote attacker, this may trigger buffer overflow.
lbs_ibss_join_existing() copys rates without checking the length
in bss descriptor from remote IBSS node.when victim connects to
remote attacker, this may trigger buffer overflow.
Fix them by putting the length check before performing copy.

This fix addresses CVE-2019-14896 and CVE-2019-14897.
Signed-off-by: Wen Huang <huangwenabc@gmail.com>

CVE-2019-14896
CVE-2019-14897

(backported from https://patchwork.kernel.org/patch/11257187/)
[smb: drop marvell subdirectory from path]
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/net/wireless/libertas/cfg.c

@@ -272,6 +272,10 @@ add_ie_rates(u8 *tlv, const u8 *ie, int *nrates)
 	int hw, ap, ap_max = ie[1];
 	u8 hw_rate;
 
+	if (ap_max > MAX_RATES) {
+		lbs_deb_assoc("invalid rates\n");
+		return tlv;
+	}
 	/* Advance past IE header */
 	ie += 2;
 
@@ -1845,6 +1849,10 @@ static int lbs_ibss_join_existing(struct lbs_private *priv,
 	} else {
 		int hw, i;
 		u8 rates_max = rates_eid[1];
+		if (rates_max > MAX_RATES) {
+			lbs_deb_join("invalid rates");
+			goto out;
+		}
 		u8 *rates = cmd.bss.rates;
 		for (hw = 0; hw < ARRAY_SIZE(lbs_rates); hw++) {
 			u8 hw_rate = lbs_rates[hw].bitrate / 5;