diff options
| author | Willem de Bruijn <willemb@google.com> | 2016-03-09 21:58:34 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-04-20 15:42:01 +0900 |
| commit | edb60bc7bb4ee6e3862aa8840a65cce47e09dcfe (patch) | |
| tree | 13a249f7f0d3332d9edbbf623d83924b2ab7ca1c /net/packet | |
| parent | abd42587771aff48c39312116e8b8db851ea0fa5 (diff) | |
packet: validate variable length ll headers
[ Upstream commit 9ed988cd591500c040b2a6257bc68543e08ceeef ]
Replace link layer header validation check ll_header_truncate with
more generic dev_validate_header.
Validation based on hard_header_len incorrectly drops valid packets
in variable length protocols, such as AX25. dev_validate_header
calls header_ops.validate for such protocols to ensure correctness
below hard_header_len.
See also http://comments.gmane.org/gmane.linux.network/401064
Fixes 9c7077622dd9 ("packet: make packet_snd fail on len smaller than l2 header")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/packet')
| -rw-r--r-- | net/packet/af_packet.c | 37 |
1 files changed, 16 insertions, 21 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 992396aa635c..da1ae0e13cb5 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1916,6 +1916,10 @@ retry: goto retry; } + if (!dev_validate_header(dev, skb->data, len)) { + err = -EINVAL; + goto out_unlock; + } if (len > (dev->mtu + dev->hard_header_len + extra_len) && !packet_extra_vlan_len_allowed(dev, skb)) { err = -EMSGSIZE; @@ -2326,18 +2330,6 @@ static void tpacket_destruct_skb(struct sk_buff *skb) sock_wfree(skb); } -static bool ll_header_truncated(const struct net_device *dev, int len) -{ - /* net device doesn't like empty head */ - if (unlikely(len < dev->hard_header_len)) { - net_warn_ratelimited("%s: packet size is too short (%d < %d)\n", - current->comm, len, dev->hard_header_len); - return true; - } - - return false; -} - static void tpacket_set_protocol(const struct net_device *dev, struct sk_buff *skb) { @@ -2420,19 +2412,19 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, if (unlikely(err < 0)) return -EINVAL; } else if (dev->hard_header_len) { - if (ll_header_truncated(dev, tp_len)) - return -EINVAL; + int hdrlen = min_t(int, dev->hard_header_len, tp_len); skb_push(skb, dev->hard_header_len); - err = skb_store_bits(skb, 0, data, - dev->hard_header_len); + err = skb_store_bits(skb, 0, data, hdrlen); if (unlikely(err)) return err; + if (!dev_validate_header(dev, skb->data, hdrlen)) + return -EINVAL; if (!skb->protocol) tpacket_set_protocol(dev, skb); - data += dev->hard_header_len; - to_write -= dev->hard_header_len; + data += hdrlen; + to_write -= hdrlen; } offset = offset_in_page(data); @@ -2763,9 +2755,6 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); if (unlikely(offset < 0)) goto out_free; - } else { - if (ll_header_truncated(dev, len)) - goto out_free; } /* Returns -EFAULT on error */ @@ -2773,6 +2762,12 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) if (err) goto out_free; + if (sock->type == SOCK_RAW && + !dev_validate_header(dev, skb->data, len)) { + err = -EINVAL; + goto out_free; + } + sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); if (!gso_type && (len > dev->mtu + reserve + extra_len) && |