This is a note to let you know that I've just added the patch titled
packet: Don't write vnet header beyond end of buffer
to the 4.9-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-don-t-write-vnet-header-beyond-end-of-buffer.patch
and it can be found in the queue-4.9 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 Thu Sep 14 23:20:08 PDT 2017
From: Benjamin Poirier <bpoirier@xxxxxxxx>
Date: Mon, 28 Aug 2017 14:29:41 -0400
Subject: packet: Don't write vnet header beyond end of buffer
From: Benjamin Poirier <bpoirier@xxxxxxxx>
[ Upstream commit edbd58be15a957f6a760c4a514cd475217eb97fd ]
... which may happen with certain values of tp_reserve and maclen.
Fixes: 58d19b19cd99 ("packet: vnet_hdr support for tpacket_rcv")
Signed-off-by: Benjamin Poirier <bpoirier@xxxxxxxx>
Cc: Willem de Bruijn <willemb@xxxxxxxxxx>
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 | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2151,6 +2151,7 @@ static int tpacket_rcv(struct sk_buff *s
struct timespec ts;
__u32 ts_status;
bool is_drop_n_account = false;
+ bool do_vnet = false;
/* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
* We may add members to them until current aligned size without forcing
@@ -2201,8 +2202,10 @@ static int tpacket_rcv(struct sk_buff *s
netoff = TPACKET_ALIGN(po->tp_hdrlen +
(maclen < 16 ? 16 : maclen)) +
po->tp_reserve;
- if (po->has_vnet_hdr)
+ if (po->has_vnet_hdr) {
netoff += sizeof(struct virtio_net_hdr);
+ do_vnet = true;
+ }
macoff = netoff - maclen;
}
if (po->tp_version <= TPACKET_V2) {
@@ -2219,8 +2222,10 @@ static int tpacket_rcv(struct sk_buff *s
skb_set_owner_r(copy_skb, sk);
}
snaplen = po->rx_ring.frame_size - macoff;
- if ((int)snaplen < 0)
+ if ((int)snaplen < 0) {
snaplen = 0;
+ do_vnet = false;
+ }
}
} else if (unlikely(macoff + snaplen >
GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
@@ -2233,6 +2238,7 @@ static int tpacket_rcv(struct sk_buff *s
if (unlikely((int)snaplen < 0)) {
snaplen = 0;
macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
+ do_vnet = false;
}
}
spin_lock(&sk->sk_receive_queue.lock);
@@ -2258,7 +2264,7 @@ static int tpacket_rcv(struct sk_buff *s
}
spin_unlock(&sk->sk_receive_queue.lock);
- if (po->has_vnet_hdr) {
+ if (do_vnet) {
if (__packet_rcv_vnet(skb, h.raw + macoff -
sizeof(struct virtio_net_hdr))) {
spin_lock(&sk->sk_receive_queue.lock);
Patches currently in stable-queue which might be from bpoirier@xxxxxxxx are
queue-4.9/packet-don-t-write-vnet-header-beyond-end-of-buffer.patch