This is a note to let you know that I've just added the patch titled packet: fix tpacket_snd max frame len to the 4.3-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-fix-tpacket_snd-max-frame-len.patch and it can be found in the queue-4.3 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 11:38:06 EST 2015 From: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Date: Wed, 11 Nov 2015 23:25:44 +0100 Subject: packet: fix tpacket_snd max frame len From: Daniel Borkmann <daniel@xxxxxxxxxxxxx> [ 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@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 | 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; Patches currently in stable-queue which might be from daniel@xxxxxxxxxxxxx are queue-4.3/packet-infer-protocol-from-ethernet-header-if-unset.patch queue-4.3/bpf-array-fix-heap-out-of-bounds-access-when-updating-elements.patch queue-4.3/ipv6-sctp-implement-sctp_v6_destroy_sock.patch queue-4.3/packet-only-allow-extra-vlan-len-on-ethernet-devices.patch queue-4.3/net-scm-fix-pax-detected-msg_controllen-overflow-in-scm_detach_fds.patch queue-4.3/packet-fix-tpacket_snd-max-frame-len.patch queue-4.3/packet-always-probe-for-transport-header.patch queue-4.3/packet-do-skb_probe_transport_header-when-we-actually-have-data.patch queue-4.3/tools-net-use-include-uapi-with-__exported_headers__.patch -- 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