3.16.72-rc1 review patch. If anyone has any objections, please let me know.
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From: Willem de Bruijn willemb@google.com
commit 486efdc8f6ce802b27e15921d2353cc740c55451 upstream.
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: 6b8d95f1795c4 ("packet: validate address length if non-zero") Suggested-by: David Laight David.Laight@aculab.com Signed-off-by: Willem de Bruijn willemb@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Ben Hutchings ben@decadent.org.uk --- net/packet/af_packet.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-)
--- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2278,8 +2278,8 @@ static int tpacket_snd(struct packet_soc 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; int len_sum = 0; int status = TP_STATUS_AVAILABLE; int hlen, tlen; @@ -2289,7 +2289,6 @@ static int tpacket_snd(struct packet_soc 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)) @@ -2299,10 +2298,13 @@ static int tpacket_snd(struct packet_soc 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) - goto out_put; + 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; @@ -2435,7 +2437,7 @@ static int packet_snd(struct socket *soc struct sk_buff *skb; struct net_device *dev; __be16 proto; - unsigned char *addr; + unsigned char *addr = NULL; int err, reserve = 0; struct virtio_net_hdr vnet_hdr = { 0 }; int offset = 0; @@ -2453,7 +2455,6 @@ static int packet_snd(struct socket *soc 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)) @@ -2461,10 +2462,13 @@ static int packet_snd(struct socket *soc 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) - goto out_unlock; + 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;