From 9812927a368cf5e7be0d060405ad45a17922db05 Mon Sep 17 00:00:00 2001 From: Vasiliy Kulikov Date: Wed, 10 Nov 2010 12:09:10 -0800 Subject: [PATCH] net: packet: fix information leak to userland commit 67286640f638f5ad41a946b9a3dc75327950248f upstream packet_getname_spkt() doesn't initialize all members of sa_data field of sockaddr struct if strlen(dev->name) < 13. This structure is then copied to userland. It leads to leaking of contents of kernel stack memory. We have to fully fill sa_data with strncpy() instead of strlcpy(). The same with packet_getname(): it doesn't initialize sll_pkttype field of sockaddr_ll. Set it to zero. Signed-off-by: Vasiliy Kulikov Signed-off-by: David S. Miller Signed-off-by: Paul Gortmaker --- net/packet/af_packet.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 243946d4809d..b1bc2d21c57f 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1645,7 +1645,7 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, rcu_read_lock(); dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); if (dev) - strlcpy(uaddr->sa_data, dev->name, 15); + strncpy(uaddr->sa_data, dev->name, 14); else memset(uaddr->sa_data, 0, 14); rcu_read_unlock(); @@ -1668,6 +1668,7 @@ static int packet_getname(struct socket *sock, struct sockaddr *uaddr, sll->sll_family = AF_PACKET; sll->sll_ifindex = po->ifindex; sll->sll_protocol = po->num; + sll->sll_pkttype = 0; rcu_read_lock(); dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); if (dev) { -- 2.39.2