Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.3 17/71] packet: fix tpacket_snd max frame len | Date | Sat, 12 Dec 2015 12:05:41 -0800 |
| |
4.3-stable review patch. If anyone has any objections, please let me know.
------------------
From: Daniel Borkmann <daniel@iogearbox.net>
[ Upstream commit 5cfb4c8d05b4409c4044cb9c05b19705c1d9818b ]
Since it's introduction in commit 69e3c75f4d54 ("net: TX_RING and packet mmap"), TX_RING could be used from SOCK_DGRAM and SOCK_RAW side. When used with SOCK_DGRAM only, the size_max > dev->mtu + reserve check should have reserve as 0, but currently, this is unconditionally set (in it's original form as dev->hard_header_len).
I think this is not correct since tpacket_fill_skb() would then take dev->mtu and dev->hard_header_len into account for SOCK_DGRAM, the extra VLAN_HLEN could be possible in both cases. Presumably, the reserve code was copied from packet_snd(), but later on missed the check. Make it similar as we have it in packet_snd().
Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-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> --- net/packet/af_packet.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
--- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2510,12 +2510,13 @@ static int tpacket_snd(struct packet_soc if (unlikely(!(dev->flags & IFF_UP))) goto out_put; - reserve = dev->hard_header_len + VLAN_HLEN; + if (po->sk.sk_socket->type == SOCK_RAW) + reserve = dev->hard_header_len; size_max = po->tx_ring.frame_size - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); - if (size_max > dev->mtu + reserve) - size_max = dev->mtu + reserve; + if (size_max > dev->mtu + reserve + VLAN_HLEN) + size_max = dev->mtu + reserve + VLAN_HLEN; do { ph = packet_current_frame(po, &po->tx_ring, @@ -2542,7 +2543,7 @@ 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 && + tp_len > dev->mtu + reserve && !packet_extra_vlan_len_allowed(dev, skb)) tp_len = -EMSGSIZE;
| |