Commit 486efdc8 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by David S. Miller
Browse files

packet: validate msg_namelen in send directly 



Packet sockets in datagram mode take a destination address. Verify its
length before passing to dev_hard_header.

Prior to 2.6.14-rc3, the send code ignored sll_halen. This is
established behavior. Directly compare msg_namelen to dev->addr_len.

Change v1->v2: initialize addr in all paths

Fixes: 6b8d95f1 ("packet: validate address length if non-zero")
Suggested-by: default avatarDavid Laight <David.Laight@aculab.com>
Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b2cf86e1

net/packet/af_packet.c

+14 −10
Original line number Diff line number Diff line
@@ -2602,8 +2602,8 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 
	void *ph;

	DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);

	bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);

	unsigned char *addr = NULL;

	int tp_len, size_max;

	unsigned char *addr;

	void *data;

	int len_sum = 0;

	int status = TP_STATUS_AVAILABLE;
@@ -2614,7 +2614,6 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 
	if (likely(saddr == NULL)) {

		dev	= packet_cached_dev_get(po);

		proto	= po->num;

		addr	= NULL;

	} else {

		err = -EINVAL;

		if (msg->msg_namelen < sizeof(struct sockaddr_ll))
@@ -2624,10 +2623,13 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 
						sll_addr)))

			goto out;

		proto	= saddr->sll_protocol;

		addr	= saddr->sll_halen ? saddr->sll_addr : NULL;

		dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);

		if (addr && dev && saddr->sll_halen < dev->addr_len)

		if (po->sk.sk_socket->type == SOCK_DGRAM) {

			if (dev && msg->msg_namelen < dev->addr_len +

				   offsetof(struct sockaddr_ll, sll_addr))

				goto out_put;

			addr = saddr->sll_addr;

		}

	}



	err = -ENXIO;
@@ -2799,7 +2801,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 
	struct sk_buff *skb;

	struct net_device *dev;

	__be16 proto;

	unsigned char *addr;

	unsigned char *addr = NULL;

	int err, reserve = 0;

	struct sockcm_cookie sockc;

	struct virtio_net_hdr vnet_hdr = { 0 };
@@ -2816,7 +2818,6 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 
	if (likely(saddr == NULL)) {

		dev	= packet_cached_dev_get(po);

		proto	= po->num;

		addr	= NULL;

	} else {

		err = -EINVAL;

		if (msg->msg_namelen < sizeof(struct sockaddr_ll))
@@ -2824,10 +2825,13 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 
		if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))

			goto out;

		proto	= saddr->sll_protocol;

		addr	= saddr->sll_halen ? saddr->sll_addr : NULL;

		dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);

		if (addr && dev && saddr->sll_halen < dev->addr_len)

		if (sock->type == SOCK_DGRAM) {

			if (dev && msg->msg_namelen < dev->addr_len +

				   offsetof(struct sockaddr_ll, sll_addr))

				goto out_unlock;

			addr = saddr->sll_addr;

		}

	}



	err = -ENXIO;

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