net: add build-time checks for msg->msg_name size
This is a follow-up patch to f3d3342602f8bc ("net: rework recvmsg
handler msg_name and msg_namelen logic").
DECLARE_SOCKADDR validates that the structure we use for writing the
name information to is not larger than the buffer which is reserved
for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR
consistently in sendmsg code paths.
Signed-off-by: Steffen Hurrle <steffen@hurrle.net>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 12f2f72..d711ecb 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1584,7 +1584,7 @@
struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
- struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
+ DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
struct sk_buff *skb = NULL;
struct net_device *dev;
__be16 proto = 0;
@@ -2196,7 +2196,7 @@
__be16 proto;
int err, reserve = 0;
void *ph;
- struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
+ DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
int tp_len, size_max;
unsigned char *addr;
@@ -2346,7 +2346,7 @@
static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
- struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
+ DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
struct sk_buff *skb;
struct net_device *dev;
__be16 proto;
@@ -2922,6 +2922,7 @@
* in, we fill it in now.
*/
if (sock->type == SOCK_PACKET) {
+ __sockaddr_check_size(sizeof(struct sockaddr_pkt));
msg->msg_namelen = sizeof(struct sockaddr_pkt);
} else {
struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;