3.13.11-ckt32 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Daniel Borkmann <dborkman@xxxxxxxxxx>
commit 52f1454f629fafbfb47ad6727e0837250e1f08c0 upstream.
Commit 57f89bfa2140 ("network: Allow af_packet to transmit +4 bytes
for VLAN packets.") added the possibility for non-mmaped frames to
send extra 4 byte for VLAN header so the MTU increases from 1500 to
1504 byte, for example.
Commit cbd89acb9eb2 ("af_packet: fix for sending VLAN frames via
packet_mmap") attempted to fix that for the mmap part but was
reverted as it caused regressions while using eth_type_trans()
on output path.
Lets just act analogous to 57f89bfa2140 and add a similar logic
to TX_RING. We presume size_max as overcharged with +4 bytes and
later on after skb has been built by tpacket_fill_skb() check
for ETH_P_8021Q header on packets larger than normal MTU. Can
be easily reproduced with a slightly modified trafgen in mmap(2)
mode, test cases:
{ fill(0xff, 12) const16(0x8100) fill(0xff, <1504|1505>) }
{ fill(0xff, 12) const16(0x0806) fill(0xff, <1500|1501>) }
Note that we need to do the test right after tpacket_fill_skb()
as sockets can have PACKET_LOSS set where we would not fail but
instead just continue to traverse the ring.
Reported-by: Mathias Kretschmer <mathias.kretschmer@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Daniel Borkmann <dborkman@xxxxxxxxxx>
Cc: Ben Greear <greearb@xxxxxxxxxxxxxxx>
Cc: Phil Sutter <phil@xxxxxx>
Tested-by: Mathias Kretschmer <mathias.kretschmer@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
net/packet/af_packet.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index b4cb15b..870046d 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2119,8 +2119,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
if (unlikely(!(dev->flags & IFF_UP)))
goto out_put;
- reserve = dev->hard_header_len;
-
+ reserve = dev->hard_header_len + VLAN_HLEN;
size_max = po->tx_ring.frame_size
- (po->tp_hdrlen - sizeof(struct sockaddr_ll));
@@ -2147,8 +2146,19 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
goto out_status;
tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
- addr, hlen);
+ addr, hlen);
+ if (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.
+ */
+ 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,
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html