linux-stable.git/include/net/dst_metadata.h, branch linux-4.9.y

net: fix a memleak when uncloning an skb dst and its metadata

2022-02-16T11:43:54+00:00

[ Upstream commit 9eeabdf17fa0ab75381045c867c370f4cc75a613 ]

When uncloning an skb dst and its associated metadata, a new
dst+metadata is allocated and later replaces the old one in the skb.
This is helpful to have a non-shared dst+metadata attached to a specific
skb.

The issue is the uncloned dst+metadata is initialized with a refcount of
1, which is increased to 2 before attaching it to the skb. When
tun_dst_unclone returns, the dst+metadata is only referenced from a
single place (the skb) while its refcount is 2. Its refcount will never
drop to 0 (when the skb is consumed), leading to a memory leak.

Fix this by removing the call to dst_hold in tun_dst_unclone, as the
dst+metadata refcount is already 1.

Fixes: fc4099f17240 ("openvswitch: Fix egress tunnel info.")
Cc: Pravin B Shelar 
Reported-by: Vlad Buslov 
Tested-by: Vlad Buslov 
Signed-off-by: Antoine Tenart 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: do not keep the dst cache when uncloning an skb dst and its metadata

2022-02-16T11:43:53+00:00

[ Upstream commit cfc56f85e72f5b9c5c5be26dc2b16518d36a7868 ]

When uncloning an skb dst and its associated metadata a new dst+metadata
is allocated and the tunnel information from the old metadata is copied
over there.

The issue is the tunnel metadata has references to cached dst, which are
copied along the way. When a dst+metadata refcount drops to 0 the
metadata is freed including the cached dst entries. As they are also
referenced in the initial dst+metadata, this ends up in UaFs.

In practice the above did not happen because of another issue, the
dst+metadata was never freed because its refcount never dropped to 0
(this will be fixed in a subsequent patch).

Fix this by initializing the dst cache after copying the tunnel
information from the old metadata to also unshare the dst cache.

Fixes: d71785ffc7e7 ("net: add dst_cache to ovs vxlan lwtunnel")
Cc: Paolo Abeni 
Reported-by: Vlad Buslov 
Tested-by: Vlad Buslov 
Signed-off-by: Antoine Tenart 
Acked-by: Paolo Abeni 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: validate lwtstate->data before returning from skb_tunnel_info()

2021-07-28T07:14:26+00:00

commit 67a9c94317402b826fc3db32afc8f39336803d97 upstream.

skb_tunnel_info() returns pointer of lwtstate->data as ip_tunnel_info
type without validation. lwtstate->data can have various types such as
mpls_iptunnel_encap, etc and these are not compatible.
So skb_tunnel_info() should validate before returning that pointer.

Splat looks like:
BUG: KASAN: slab-out-of-bounds in vxlan_get_route+0x418/0x4b0 [vxlan]
Read of size 2 at addr ffff888106ec2698 by task ping/811

CPU: 1 PID: 811 Comm: ping Not tainted 5.13.0+ #1195
Call Trace:
 dump_stack_lvl+0x56/0x7b
 print_address_description.constprop.8.cold.13+0x13/0x2ee
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 kasan_report.cold.14+0x83/0xdf
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 vxlan_get_route+0x418/0x4b0 [vxlan]
 [ ... ]
 vxlan_xmit_one+0x148b/0x32b0 [vxlan]
 [ ... ]
 vxlan_xmit+0x25c5/0x4780 [vxlan]
 [ ... ]
 dev_hard_start_xmit+0x1ae/0x6e0
 __dev_queue_xmit+0x1f39/0x31a0
 [ ... ]
 neigh_xmit+0x2f9/0x940
 mpls_xmit+0x911/0x1600 [mpls_iptunnel]
 lwtunnel_xmit+0x18f/0x450
 ip_finish_output2+0x867/0x2040
 [ ... ]

Fixes: 61adedf3e3f1 ("route: move lwtunnel state to dst_entry")
Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/dst: Utility functions to build dst_metadata without supplying an skb

2016-09-11T03:53:55+00:00

Extract __ip_tun_set_dst() and __ipv6_tun_set_dst() out of
ip_tun_rx_dst() and ipv6_tun_rx_dst(), to be used without supplying an
skb.

Signed-off-by: Amir Vadai 
Signed-off-by: Hadar Hen Zion 
Acked-by: Jiri Pirko 
Reviewed-by: Shmulik Ladkani 
Signed-off-by: David S. Miller

ip_tunnel: add support for setting flow label via collect metadata

2016-03-11T20:14:26+00:00

This patch extends udp_tunnel6_xmit_skb() to pass in the IPv6 flow label
from call sites. Currently, there's no such option and it's always set to
zero when writing ip6_flow_hdr(). Add a label member to ip_tunnel_key, so
that flow-based tunnels via collect metadata frontends can make use of it.
vxlan and geneve will be converted to add flow label support separately.

Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

net: add dst_cache to ovs vxlan lwtunnel

2016-02-17T01:21:48+00:00

In case of UDP traffic with datagram length
below MTU this give about 2% performance increase
when tunneling over ipv4 and about 60% when tunneling
over ipv6

Signed-off-by: Paolo Abeni 
Suggested-and-acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

gro: Make GRO aware of lightweight tunnels.

2016-01-21T02:48:38+00:00

GRO is currently not aware of tunnel metadata generated by lightweight
tunnels and stored in the dst. This leads to two possible problems:
 * Incorrectly merging two frames that have different metadata.
 * Leaking of allocated metadata from merged frames.

This avoids those problems by comparing the tunnel information before
merging, similar to how we handle other metadata (such as vlan tags),
and releasing any state when we are done.

Reported-by: John 
Fixes: 2e15ea39 ("ip_gre: Add support to collect tunnel metadata.")
Signed-off-by: Jesse Gross 
Acked-by: Eric Dumazet 
Acked-by: Thomas Graf 
Signed-off-by: David S. Miller

tun_dst: Fix potential NULL dereference

2015-11-05T02:59:22+00:00

In tun_dst_unclone() the return value of skb_metadata_dst() is checked
for being NULL after it is dereferenced. Fix this by moving the
dereference after the NULL check.

Found by the Coverity scanner (CID 1338068).

Fixes: fc4099f17240 ("openvswitch: Fix egress tunnel info.")
Cc: Pravin B Shelar 
Signed-off-by: Tobias Klauser 
Signed-off-by: David S. Miller

openvswitch: Fix egress tunnel info.

2015-10-23T02:39:25+00:00

While transitioning to netdev based vport we broke OVS
feature which allows user to retrieve tunnel packet egress
information for lwtunnel devices.  Following patch fixes it
by introducing ndo operation to get the tunnel egress info.
Same ndo operation can be used for lwtunnel devices and compat
ovs-tnl-vport devices. So after adding such device operation
we can remove similar operation from ovs-vport.

Fixes: 614732eaa12d ("openvswitch: Use regular VXLAN net_device device").
Signed-off-by: Pravin B Shelar 
Signed-off-by: David S. Miller

tun_dst: Remove opts_size

2015-09-01T04:23:42+00:00

opts_size is only written and never read. Following patch
removes this unused variable.

Signed-off-by: Pravin B Shelar 
Signed-off-by: David S. Miller