This is a note to let you know that I've just added the patch titled
packet: only allow extra vlan len on ethernet devices
to the 4.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
packet-only-allow-extra-vlan-len-on-ethernet-devices.patch
and it can be found in the queue-4.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Dec 11 11:38:35 EST 2015
From: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Date: Wed, 11 Nov 2015 23:25:42 +0100
Subject: packet: only allow extra vlan len on ethernet devices
From: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
[ Upstream commit 3c70c132488794e2489ab045559b0ce0afcf17de ]
Packet sockets can be used by various net devices and are not
really restricted to ARPHRD_ETHER device types. However, when
currently checking for the extra 4 bytes that can be transmitted
in VLAN case, our assumption is that we generally probe on
ARPHRD_ETHER devices. Therefore, before looking into Ethernet
header, check the device type first.
This also fixes the issue where non-ARPHRD_ETHER devices could
have no dev->hard_header_len in TX_RING SOCK_RAW case, and thus
the check would test unfilled linear part of the skb (instead
of non-linear).
Fixes: 57f89bfa2140 ("network: Allow af_packet to transmit +4 bytes for VLAN packets.")
Fixes: 52f1454f629f ("packet: allow to transmit +4 byte in TX_RING slot for VLAN case")
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/packet/af_packet.c | 60 ++++++++++++++++++++-----------------------------
1 file changed, 25 insertions(+), 35 deletions(-)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1622,6 +1622,20 @@ static void fanout_release(struct sock *
kfree_rcu(po->rollover, rcu);
}
+static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
+ struct sk_buff *skb)
+{
+ /* Earlier code assumed this would be a VLAN pkt, double-check
+ * this now that we have the actual packet in hand. We can only
+ * do this check on Ethernet devices.
+ */
+ if (unlikely(dev->type != ARPHRD_ETHER))
+ return false;
+
+ skb_reset_mac_header(skb);
+ return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
+}
+
static const struct proto_ops packet_ops;
static const struct proto_ops packet_ops_spkt;
@@ -1783,18 +1797,10 @@ retry:
goto retry;
}
- if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
- /* Earlier code assumed this would be a VLAN pkt,
- * double-check this now that we have the actual
- * packet in hand.
- */
- struct ethhdr *ehdr;
- skb_reset_mac_header(skb);
- ehdr = eth_hdr(skb);
- if (ehdr->h_proto != htons(ETH_P_8021Q)) {
- err = -EMSGSIZE;
- goto out_unlock;
- }
+ if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
+ !packet_extra_vlan_len_allowed(dev, skb)) {
+ err = -EMSGSIZE;
+ goto out_unlock;
}
skb->protocol = proto;
@@ -2406,18 +2412,10 @@ static int tpacket_snd(struct packet_soc
tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
addr, hlen);
if (likely(tp_len >= 0) &&
- tp_len > dev->mtu + dev->hard_header_len) {
- struct ethhdr *ehdr;
- /* Earlier code assumed this would be a VLAN pkt,
- * double-check this now that we have the actual
- * packet in hand.
- */
+ tp_len > dev->mtu + dev->hard_header_len &&
+ !packet_extra_vlan_len_allowed(dev, skb))
+ tp_len = -EMSGSIZE;
- skb_reset_mac_header(skb);
- ehdr = eth_hdr(skb);
- if (ehdr->h_proto != htons(ETH_P_8021Q))
- tp_len = -EMSGSIZE;
- }
if (unlikely(tp_len < 0)) {
if (po->tp_loss) {
__packet_set_status(po, ph,
@@ -2638,18 +2636,10 @@ static int packet_snd(struct socket *soc
sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
- if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
- /* Earlier code assumed this would be a VLAN pkt,
- * double-check this now that we have the actual
- * packet in hand.
- */
- struct ethhdr *ehdr;
- skb_reset_mac_header(skb);
- ehdr = eth_hdr(skb);
- if (ehdr->h_proto != htons(ETH_P_8021Q)) {
- err = -EMSGSIZE;
- goto out_free;
- }
+ if (!gso_type && (len > dev->mtu + reserve + extra_len) &&
+ !packet_extra_vlan_len_allowed(dev, skb)) {
+ err = -EMSGSIZE;
+ goto out_free;
}
skb->protocol = proto;
Patches currently in stable-queue which might be from daniel@xxxxxxxxxxxxx are
queue-4.2/packet-infer-protocol-from-ethernet-header-if-unset.patch
queue-4.2/bpf-array-fix-heap-out-of-bounds-access-when-updating-elements.patch
queue-4.2/ipv6-sctp-implement-sctp_v6_destroy_sock.patch
queue-4.2/packet-only-allow-extra-vlan-len-on-ethernet-devices.patch
queue-4.2/net-scm-fix-pax-detected-msg_controllen-overflow-in-scm_detach_fds.patch
queue-4.2/packet-fix-tpacket_snd-max-frame-len.patch
queue-4.2/packet-always-probe-for-transport-header.patch
queue-4.2/packet-do-skb_probe_transport_header-when-we-actually-have-data.patch
queue-4.2/tools-net-use-include-uapi-with-__exported_headers__.patch
--
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