Commit 67286640 authored by Vasiliy Kulikov's avatar Vasiliy Kulikov Committed by David S. Miller

net: packet: fix information leak to userland

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: default avatarVasiliy Kulikov <segooon@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 57fe93b3
...@@ -1719,7 +1719,7 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, ...@@ -1719,7 +1719,7 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
rcu_read_lock(); rcu_read_lock();
dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
if (dev) if (dev)
strlcpy(uaddr->sa_data, dev->name, 15); strncpy(uaddr->sa_data, dev->name, 14);
else else
memset(uaddr->sa_data, 0, 14); memset(uaddr->sa_data, 0, 14);
rcu_read_unlock(); rcu_read_unlock();
...@@ -1742,6 +1742,7 @@ static int packet_getname(struct socket *sock, struct sockaddr *uaddr, ...@@ -1742,6 +1742,7 @@ static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
sll->sll_family = AF_PACKET; sll->sll_family = AF_PACKET;
sll->sll_ifindex = po->ifindex; sll->sll_ifindex = po->ifindex;
sll->sll_protocol = po->num; sll->sll_protocol = po->num;
sll->sll_pkttype = 0;
rcu_read_lock(); rcu_read_lock();
dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
if (dev) { if (dev) {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment