diff options
| author | Willem de Bruijn <willemb@google.com> | 2019-04-29 11:53:18 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-05-01 11:28:35 -0400 |
| commit | 486efdc8f6ce802b27e15921d2353cc740c55451 (patch) | |
| tree | 38f6396a1f53717bdd1247a75abb4e632fe2e2ea /net/packet/af_packet.c | |
| parent | b2cf86e1563e33a14a1c69b3e508d15dc12f804c (diff) | |
| download | lwn-486efdc8f6ce802b27e15921d2353cc740c55451.tar.gz lwn-486efdc8f6ce802b27e15921d2353cc740c55451.zip | |
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: 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>
Diffstat (limited to 'net/packet/af_packet.c')
| -rw-r--r-- | net/packet/af_packet.c | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 7d361cd53ad5..9b81813dd16a 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -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) - 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; @@ -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) - 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; |