linux-stable.git/drivers/net/ipvlan, branch v4.4.185

ipvlan: disallow userns cap_net_admin to change global mode/flags

2019-03-23T07:44:31+00:00

[ Upstream commit 7cc9f7003a969d359f608ebb701d42cafe75b84a ]

When running Docker with userns isolation e.g. --userns-remap="default"
and spawning up some containers with CAP_NET_ADMIN under this realm, I
noticed that link changes on ipvlan slave device inside that container
can affect all devices from this ipvlan group which are in other net
namespaces where the container should have no permission to make changes
to, such as the init netns, for example.

This effectively allows to undo ipvlan private mode and switch globally to
bridge mode where slaves can communicate directly without going through
hostns, or it allows to switch between global operation mode (l2/l3/l3s)
for everyone bound to the given ipvlan master device. libnetwork plugin
here is creating an ipvlan master and ipvlan slave in hostns and a slave
each that is moved into the container's netns upon creation event.

* In hostns:

  # ip -d a
  [...]
  8: cilium_host@bond0:  mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether 0c:c4:7a:e1:3d:cc brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 65535
     ipvlan  mode l3 bridge numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
     inet 10.41.0.1/32 scope link cilium_host
       valid_lft forever preferred_lft forever
  [...]

* Spawn container & change ipvlan mode setting inside of it:

  # docker run -dt --cap-add=NET_ADMIN --network cilium-net --name client -l app=test cilium/netperf
  9fff485d69dcb5ce37c9e33ca20a11ccafc236d690105aadbfb77e4f4170879c

  # docker exec -ti client ip -d a
  [...]
  10: cilium0@if4:  mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
      link/ether 0c:c4:7a:e1:3d:cc brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 65535
      ipvlan  mode l3 bridge numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
      inet 10.41.197.43/32 brd 10.41.197.43 scope global cilium0
         valid_lft forever preferred_lft forever

  # docker exec -ti client ip link change link cilium0 name cilium0 type ipvlan mode l2

  # docker exec -ti client ip -d a
  [...]
  10: cilium0@if4:  mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
      link/ether 0c:c4:7a:e1:3d:cc brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 65535
      ipvlan  mode l2 bridge numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
      inet 10.41.197.43/32 brd 10.41.197.43 scope global cilium0
         valid_lft forever preferred_lft forever

* In hostns (mode switched to l2):

  # ip -d a
  [...]
  8: cilium_host@bond0:  mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
      link/ether 0c:c4:7a:e1:3d:cc brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 65535
      ipvlan  mode l2 bridge numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
      inet 10.41.0.1/32 scope link cilium_host
         valid_lft forever preferred_lft forever
  [...]

Same l3 -> l2 switch would also happen by creating another slave inside
the container's network namespace when specifying the existing cilium0
link to derive the actual (bond0) master:

  # docker exec -ti client ip link add link cilium0 name cilium1 type ipvlan mode l2

  # docker exec -ti client ip -d a
  [...]
  2: cilium1@if4:  mtu 1500 qdisc noop state DOWN group default qlen 1000
      link/ether 0c:c4:7a:e1:3d:cc brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 65535
      ipvlan  mode l2 bridge numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
  10: cilium0@if4:  mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
      link/ether 0c:c4:7a:e1:3d:cc brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 65535
      ipvlan  mode l2 bridge numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
      inet 10.41.197.43/32 brd 10.41.197.43 scope global cilium0
         valid_lft forever preferred_lft forever

* In hostns:

  # ip -d a
  [...]
  8: cilium_host@bond0:  mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
      link/ether 0c:c4:7a:e1:3d:cc brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 65535
      ipvlan  mode l2 bridge numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
      inet 10.41.0.1/32 scope link cilium_host
         valid_lft forever preferred_lft forever
  [...]

One way to mitigate it is to check CAP_NET_ADMIN permissions of
the ipvlan master device's ns, and only then allow to change
mode or flags for all devices bound to it. Above two cases are
then disallowed after the patch.

Signed-off-by: Daniel Borkmann 
Acked-by: Mahesh Bandewar 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipvlan: add L2 check for packets arriving via virtual devices

2018-03-22T08:23:30+00:00

[ Upstream commit 92ff42645028fa6f9b8aa767718457b9264316b4 ]

Packets that don't have dest mac as the mac of the master device should
not be entertained by the IPvlan rx-handler. This is mostly true as the
packet path mostly takes care of that, except when the master device is
a virtual device. As demonstrated in the following case -

  ip netns add ns1
  ip link add ve1 type veth peer name ve2
  ip link add link ve2 name iv1 type ipvlan mode l2
  ip link set dev iv1 netns ns1
  ip link set ve1 up
  ip link set ve2 up
  ip -n ns1 link set iv1 up
  ip addr add 192.168.10.1/24 dev ve1
  ip -n ns1 addr 192.168.10.2/24 dev iv1
  ping -c2 192.168.10.2
  
  ip neigh show dev ve1
  ip neigh show 192.168.10.2 lladdr  dev ve1
  ping -c2 192.168.10.2
  

This patch adds that missing check in the IPvlan rx-handler.

Reported-by: Amit Sikka 
Signed-off-by: Mahesh Bandewar 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ipvlan: Add the skb->mark as flow4's member to lookup route

2018-02-25T10:03:40+00:00

[ Upstream commit a98a4ebc8c61d20f0150d6be66e0e65223a347af ]

Current codes don't use skb->mark to assign flowi4_mark, it would
make the policy route rule with fwmark doesn't work as expected.

Signed-off-by: Gao Feng 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ipvlan: fix ipv6 outbound device

2017-12-16T09:33:56+00:00

[ Upstream commit ca29fd7cce5a6444d57fb86517589a1a31c759e1 ]

When process the outbound packet of ipv6, we should assign the master
device to output device other than input device.

Signed-off-by: Keefe Liu 
Acked-by: Mahesh Bandewar 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ipvlan: fix use after free of skb

2015-11-17T19:39:29+00:00

ipvlan_handle_frame is a rx_handler, and when it returns a value other
than RX_HANDLER_CONSUMED (here, NET_RX_DROP aka RX_HANDLER_ANOTHER),
__netif_receive_skb_core expects that the skb still exists and will
process it further, but we just freed it.

Fixes: 2ad7bf363841 ("ipvlan: Initial check-in of the IPVLAN driver.")
Signed-off-by: Sabrina Dubroca 
Signed-off-by: David S. Miller

ipvlan: fix leak in ipvlan_rcv_frame

2015-11-17T19:39:28+00:00

Pass a **skb to ipvlan_rcv_frame so that if skb_share_check returns a
new skb, we actually use it during further processing.

It's safe to ignore the new skb in the ipvlan_xmit_* functions, because
they call ipvlan_rcv_frame with local == true, so that dev_forward_skb
is called and always takes ownership of the skb.

Fixes: 2ad7bf363841 ("ipvlan: Initial check-in of the IPVLAN driver.")
Signed-off-by: Sabrina Dubroca 
Signed-off-by: David S. Miller

ipvlan: read direct ifindex instead of iflink

2015-10-22T13:39:08+00:00

In the ipv4 outbound path of an ipvlan device in l3 mode, the ifindex is
being grabbed from dev_get_iflink. This works for the physical device
case, since as the documentation of that function notes: "Physical
interfaces have the same 'ifindex' and 'iflink' values.".  However, if
the master device is a veth, and the pairs are in separate net
namespaces, the route lookup will fail with -ENODEV due to outer veth
pair being in a separate namespace from the ipvlan master/routing
namespace.

  ns0    |   ns1    |   ns2
 veth0a--|--veth0b--|--ipvl0

In ipvlan_process_v4_outbound(), a packet sent from ipvl0 in the above
configuration will pass fl.flowi4_oif == veth0a to
ip_route_output_flow(), but *net == ns1.

Notice also that ipv6 processing is not using iflink. Since there is a
discrepancy in usage, fixup both v4 and v6 case to use local dev
variable.

Tested this with l3 ipvlan on top of veth, as well as with single
physical interface in the top namespace.

Signed-off-by: Brenden Blanco 
Reviewed-by: Jiri Benc 
Acked-by: Mahesh Bandewar 
Signed-off-by: David S. Miller

ipv4, ipv6: Pass net into ip_local_out and ip6_local_out

2015-10-08T11:27:02+00:00

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller

ipvlan: Cache net in ipvlan_process_v4_outbound and ipvlan_process_v6_outbound

2015-10-08T11:27:01+00:00

Compute net once in ipvlan_process_v4_outbound and
ipvlan_process_v6_outbound and store it in a variable so that net does
not need to be recomputed next time it is used.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller

ipv6: Merge ip6_local_out and ip6_local_out_sk

2015-10-08T11:26:58+00:00

Stop hidding the sk parameter with an inline helper function and make
all of the callers pass it, so that it is clear what the function is
doing.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller