From: Sven Eckelmann Date: Fri, 31 Aug 2018 13:08:44 +0000 (+0200) Subject: batman-adv: Avoid probe ELP information leak X-Git-Tag: v4.19-rc6~26^2~29^2~10 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=88d0895d0ea9d4431507d576c963f2ff9918144d;p=users%2Fhch%2Fmisc.git batman-adv: Avoid probe ELP information leak The probe ELPs for WiFi interfaces are expanded to contain at least BATADV_ELP_MIN_PROBE_SIZE bytes. This is usually a lot more than the number of bytes which the template ELP packet requires. These extra padding bytes were not initialized and thus could contain data which were previously stored at the same location. It is therefore required to set it to some predefined or random values to avoid leaking private information from the system transmitting these kind of packets. Fixes: e4623c913508 ("batman-adv: Avoid probe ELP information leak") Signed-off-by: Sven Eckelmann Acked-by: Antonio Quartulli Signed-off-by: Simon Wunderlich --- diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c index 71c20c1d4002..e103c759b7ab 100644 --- a/net/batman-adv/bat_v_elp.c +++ b/net/batman-adv/bat_v_elp.c @@ -241,7 +241,7 @@ batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh) * the packet to be exactly of that size to make the link * throughput estimation effective. */ - skb_put(skb, probe_len - hard_iface->bat_v.elp_skb->len); + skb_put_zero(skb, probe_len - hard_iface->bat_v.elp_skb->len); batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "Sending unicast (probe) ELP packet on interface %s to %pM\n",