commit 58e2071742e38f29f051b709a5cca014ba51166f upstream.
This patch fixes a tunnel_dst null pointer dereference due to lockless
access in the tunnel egress path. When deleting a vlan tunnel the
tunnel_dst pointer is set to NULL without waiting a grace period (i.e.
while it's still usable) and packets egressing are dereferencing it
without checking. Use READ/WRITE_ONCE to annotate the lockless use of
tunnel_id, use RCU for accessing tunnel_dst and make sure it is read
only once and checked in the egress path. The dst is already properly RCU
protected so we don't need to do anything fancy than to make sure
tunnel_id and tunnel_dst are read only once and checked in the egress path.
Cc: stable@vger.kernel.org
Fixes: 11538d039ac6 ("bridge: vlan dst_metadata hooks in ingress and egress paths")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: efa5356b0d97 ("bridge: per vlan dst_metadata netlink support")
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
- ingress hook:
- if port is a tunnel port, use tunnel info in
attached dst_metadata to map it to a local vlan
- egress hook:
- if port is a tunnel port, use tunnel info attached to
vlan to set dst_metadata on the skb
CC: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds support to attach per vlan tunnel info dst
metadata. This enables bridge driver to map vlan to tunnel_info
at ingress and egress. It uses the kernel dst_metadata infrastructure.
The initial use case is vlan to vni bridging, but the api is generic
to extend to any tunnel_info in the future:
- Uapi to configure/unconfigure/dump per vlan tunnel data
- netlink functions to configure vlan and tunnel_info mapping
- Introduces bridge port flag BR_LWT_VLAN to enable attach/detach
dst_metadata to bridged packets on ports. off by default.
- changes to existing code is mainly refactor some existing vlan
handling netlink code + hooks for new vlan tunnel code
- I have kept the vlan tunnel code isolated in separate files.
- most of the netlink vlan tunnel code is handling of vlan-tunid
ranges (follows the vlan range handling code). To conserve space
vlan-tunid by default are always dumped in ranges if applicable.
Use case:
example use for this is a vxlan bridging gateway or vtep
which maps vlans to vn-segments (or vnis).
iproute2 example (patched and pruned iproute2 output to just show
relevant fdb entries):
example shows same host mac learnt on two vni's and
vlan 100 maps to vni 1000, vlan 101 maps to vni 1001
before (netdev per vni):
$bridge fdb show | grep "00:02:00:00:00:03"
00:02:00:00:00:03 dev vxlan1001 vlan 101 master bridge
00:02:00:00:00:03 dev vxlan1001 dst 12.0.0.8 self
00:02:00:00:00:03 dev vxlan1000 vlan 100 master bridge
00:02:00:00:00:03 dev vxlan1000 dst 12.0.0.8 self
after this patch with collect metdata in bridged mode (single netdev):
$bridge fdb show | grep "00:02:00:00:00:03"
00:02:00:00:00:03 dev vxlan0 vlan 101 master bridge
00:02:00:00:00:03 dev vxlan0 src_vni 1001 dst 12.0.0.8 self
00:02:00:00:00:03 dev vxlan0 vlan 100 master bridge
00:02:00:00:00:03 dev vxlan0 src_vni 1000 dst 12.0.0.8 self
CC: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
