linux-stable.git/net/netfilter, branch v5.17.2

netfilter: nf_conntrack_tcp: preserve liberal flag in tcp options

2022-04-08T11:58:31+00:00

[ Upstream commit f2dd495a8d589371289981d5ed33e6873df94ecc ]

Do not reset IP_CT_TCP_FLAG_BE_LIBERAL flag in out-of-sync scenarios
coming before the TCP window tracking, otherwise such connections will
fail in the window check.

Update tcp_options() to leave this flag in place and add a new helper
function to reset the tcp window state.

Based on patch from Sven Auhagen.

Fixes: c4832c7bbc3f ("netfilter: nf_ct_tcp: improve out-of-sync situation in TCP tracking")
Tested-by: Sven Auhagen 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: conntrack: Add and use nf_ct_set_auto_assign_helper_warned()

2022-04-08T11:58:21+00:00

[ Upstream commit 31d0bb9763efad30377505f3467f958d1ebe1e3d ]

The function sets the pernet boolean to avoid the spurious warning from
nf_ct_lookup_helper() when assigning conntrack helpers via nftables.

Fixes: 1a64edf54f55 ("netfilter: nft_ct: add helper set support")
Signed-off-by: Phil Sutter 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: flowtable: Fix QinQ and pppoe support for inet table

2022-04-08T11:58:19+00:00

[ Upstream commit 0492d857636e1c52cd71594a723c4b26a7b31978 ]

nf_flow_offload_inet_hook() does not check for 802.1q and PPPoE.
Fetch inner ethertype from these encapsulation protocols.

Fixes: 72efd585f714 ("netfilter: flowtable: add pppoe support")
Fixes: 4cd91f7c290f ("netfilter: flowtable: add vlan support")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_tables: validate registers coming from userspace.

2022-03-28T08:03:20+00:00

commit 6e1acfa387b9ff82cfc7db8cc3b6959221a95851 upstream.

Bail out in case userspace uses unsupported registers.

Fixes: 49499c3e6e18 ("netfilter: nf_tables: switch registers to 32 bit addressing")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: initialize registers in nft_do_chain()

2022-03-28T08:03:20+00:00

commit 4c905f6740a365464e91467aa50916555b28213d upstream.

Initialize registers to avoid stack leak into userspace.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: disable register tracking

2022-03-12T15:07:38+00:00

The register tracking infrastructure is incomplete, it might lead to
generating incorrect ruleset bytecode, disable it by now given we are
late in the release process.

Signed-off-by: Pablo Neira Ayuso

Revert "netfilter: conntrack: tag conntracks picked up in local out hook"

2022-03-08T16:28:38+00:00

This was a prerequisite for the ill-fated
"netfilter: nat: force port remap to prevent shadowing well-known ports".

As this has been reverted, this change can be backed out too.

Signed-off-by: Florian Westphal

Revert "netfilter: nat: force port remap to prevent shadowing well-known ports"

2022-03-08T12:52:11+00:00

This reverts commit 878aed8db324bec64f3c3f956e64d5ae7375a5de.

This change breaks existing setups where conntrack is used with
asymmetric paths.

In these cases, the NAT transformation occurs on the syn-ack instead of
the syn:

1. SYN    x:12345 -> y -> 443 // sent by initiator, receiverd by responder
2. SYNACK y:443 -> x:12345 // First packet seen by conntrack, as sent by responder
3. tuple_force_port_remap() gets called, sees:
  'tcp from 443 to port 12345 NAT' -> pick a new source port, inititor receives
4. SYNACK y:$RANDOM -> x:12345   // connection is never established

While its possible to avoid the breakage with NOTRACK rules, a kernel
update should not break working setups.

An alternative to the revert is to augment conntrack to tag
mid-stream connections plus more code in the nat core to skip NAT
for such connections, however, this leads to more interaction/integration
between conntrack and NAT.

Therefore, revert, users will need to add explicit nat rules to avoid
port shadowing.

Link: https://lore.kernel.org/netfilter-devel/20220302105908.GA5852@breakpoint.cc/#R
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2051413
Signed-off-by: Florian Westphal

net/sched: act_ct: Fix flow table lookup failure with no originating ifindex

2022-03-01T21:08:31+00:00

After cited commit optimizted hw insertion, flow table entries are
populated with ifindex information which was intended to only be used
for HW offload. This tuple ifindex is hashed in the flow table key, so
it must be filled for lookup to be successful. But tuple ifindex is only
relevant for the netfilter flowtables (nft), so it's not filled in
act_ct flow table lookup, resulting in lookup failure, and no SW
offload and no offload teardown for TCP connection FIN/RST packets.

To fix this, add new tc ifindex field to tuple, which will
only be used for offloading, not for lookup, as it will not be
part of the tuple hash.

Fixes: 9795ded7f924 ("net/sched: act_ct: Fill offloading tuple iifidx")
Signed-off-by: Paul Blakey 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_queue: handle socket prefetch

2022-03-01T10:51:15+00:00

In case someone combines bpf socket assign and nf_queue, then we will
queue an skb who references a struct sock that did not have its
reference count incremented.

As we leave rcu protection, there is no guarantee that skb->sk is still
valid.

For refcount-less skb->sk case, try to increment the reference count
and then override the destructor.

In case of failure we have two choices: orphan the skb and 'delete'
preselect or let nf_queue() drop the packet.

Do the latter, it should not happen during normal operation.

Fixes: cf7fbe660f2d ("bpf: Add socket assign support")
Acked-by: Joe Stringer 
Signed-off-by: Florian Westphal