linux-stable.git/include/net/netfilter, branch v7.1.5

netfilter: flowtable: support IPIP tunnel with direct xmit

2026-07-24T14:20:53+00:00

commit fa7395c02d95e51bad2952325d2d6503bfbad437 upstream.

The combination of IPIP tunnel with direct xmit, eg. bridge device,
breaks because no dst_entry is provided to check the skb headroom and to
set the iph->frag_off field. This leads to invalid dst usage and can
trigger a crash in the tunnel transmit path.

Fix this by moving dst_cache and dst_cookie out of the runtime union so
that they can be shared by neighbour, xfrm, and direct tunnel flows.
For FLOW_OFFLOAD_XMIT_DIRECT tuples carrying tunnel metadata, preserve
route state in these shared fields and release it through the common
dst release path.

Since dst_entry is now available to the three supported xmit modes and
dst_release() already deals with NULL dst, remove the xmit type check
in nft_flow_dst_release(). Moreover, skip the check if the dst entry
is NULL in nf_flow_dst_check() which is now the case for the direct
xmit case.

Based on patch from Rein Wei .

Fixes: d30301ba4b07 ("netfilter: flowtable: Add IPIP tx sw acceleration")
Cc: stable@vger.kernel.org
Reported-by: Yuan Tan 
Reported-by: Xin Liu 
Reported-by: Zhengyang Chen 
Reported-by: Ren Wei 
Signed-off-by: Pablo Neira Ayuso 
Acked-by: Lorenzo Bianconi 
Signed-off-by: Florian Westphal 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_queue: pin bridge device while NFQUEUE holds fake dst

2026-07-24T14:20:53+00:00

commit c9c9b37f8c5505224e8d206184df3bb668ee00cf upstream.

The br_netfilter fake rtable is embedded in struct net_bridge and is
attached to bridged packets with skb_dst_set_noref(). If such a packet is
queued to NFQUEUE, __nf_queue() upgrades that fake dst with
skb_dst_force().

At that point the queued skb can hold a real dst reference after bridge
teardown has started. The problem is not that every bridged packet needs
its own dst reference. The problem is that NFQUEUE can keep the bridge
private fake dst alive after unregister begins.

Fix this by keeping the bridge fake dst model unchanged and pinning the
bridge master device only while the packet sits in NFQUEUE. Record the
bridge device in nf_queue_entry when the queued skb carries a bridge fake
dst, take a device reference for the queue lifetime, and drop it when the
queue entry is freed.

Also make sure queued entries are reaped when that bridge device goes
down, and drop the redundant nf_bridge_info_exists() test from the fake
dst detection.

This keeps netdev_priv(br->dev) alive until verdict completion, so the
embedded fake rtable and its metrics backing storage cannot be freed out
from under dst_release(). It also avoids the constant refcount bump and
avoids using ipv4-specific dst helpers for IPv6 bridge traffic.

Fixes: 34666d467cbf ("netfilter: bridge: move br_netfilter out of the core")
Cc: stable@kernel.org
Reported-by: Yuan Tan 
Reported-by: Yifan Wu 
Reported-by: Juefei Pu 
Reported-by: Xin Liu 
Signed-off-by: Haoze Xie 
Signed-off-by: Ren Wei 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conntrack_expect: store master_tuple in expectation

2026-07-24T14:20:27+00:00

[ Upstream commit 979c13114c0bb6ab9135e2c93e00c79c412aef09 ]

Store master conntrack tuple in the expectation since exp->master might
refer to a different conntrack when accessed from rcu read side lock
area due to typesafe rcu rules.

Fixes: 02a3231b6d82 ("netfilter: nf_conntrack_expect: store netns and zone in expectation")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_conntrack_expect: use conntrack GC to reap expectations

2026-07-24T14:20:27+00:00

[ Upstream commit b8b09dc2bf35a00d4e0556b5d6308c7b917ebda2 ]

This patch replaces the timer API by GC worker approach for
expectations, as it already happened in many other subsystems.

Use the existing conntrack GC worker to iterate over the local list of
expectations in the master conntrack to reap expired expectations.
Check IPS_HELPER_BIT to run GC for expectations, set it on for nft_ct
expectation which nevers sets it. Hold the expectation spinlock while
iterating over the master conntrack expectation list to synchronize with
nf_ct_remove_expectations(). This also performs runtime packet path
garbage collection through the expectation insertion and lookup
functions while walking over one of the chains of the global expectation
hashtables. Unconfirmed conntrack entries are skipped since ct->ext can
be reallocated and dying are skipped since those will be gone soon.
Set on IPS_HELPER_BIT if the helper ct extension is added, then the new
GC worker does not need to bump the ct refcount to check if the ct->ext
helper is available.

This removes the extra bump on the refcount for expectation timers, this
allows to remove several nf_ct_expect_put() calls after the unlink,
after this update only refcount remains at 1 while on the expectation
hashes.

This patch implicitly addresses a race with the existing timer API
allowing an expectation to access a stale exp->master pointer which has
been already released when expectation removal loses races with an
expiring timer, ie. timer_del() reporting false.

Add a new NF_CT_EXPECT_DEAD flag to reap this expectation via GC. This
is needed by nf_conntrack_unexpect_related() which is called in error
paths to invalidate newly created expectations that has been added into
the hashes. These expectactions cannot be inmediately released as GC or
nf_ct_remove_expectations() could race to make it. On expectation
insert, the runtime GC reaps stale expectations before checking the
expectation limit set by policy.

Set current timestamp in nf_ct_expect_alloc(), then add the expectation
policy timeout (or custom timeout specified added on top of this) to
specify the expectation lifetime.

Fixes: bffcaad9afdf ("netfilter: ctnetlink: ensure safe access to master conntrack")
Signed-off-by: Pablo Neira Ayuso
Stable-dep-of: 979c13114c0b ("netfilter: nf_conntrack_expect: store master_tuple in expectation")
Signed-off-by: Sasha Levin

netfilter: conntrack: check NULL when retrieving ct extension

2026-07-24T14:20:26+00:00

[ Upstream commit e3cd138e560764299965fba5ec5240281a7faca2 ]

nf_ct_ext_find() might return NULL if ct extension is not found.

Add also the null checks to:

- nfct_help()
- nfct_help_data()
- nfct_seqadj()
- nfct_nat()

This is defensive, for safety reasons.

nf_ct_ext_find() used to return NULL if the extension is stale for
unconfirmed conntracks if the genid validation fails.

Skip NULL check in nf_nat_inet_fn() given this is valid to be NULL
for non-initialized ct nat extensions.

While at it, fetch ct helper area in nf_ct_expect_related_report() only
once and pass it on to other ancilliary functions. Replace WARN_ON()
by WARN_ON_ONCE() in nf_ct_unlink_expect_report().

Signed-off-by: Pablo Neira Ayuso 
Stable-dep-of: 979c13114c0b ("netfilter: nf_conntrack_expect: store master_tuple in expectation")
Signed-off-by: Sasha Levin

netfilter: nf_conntrack_pptp: move GRE specific cleanup to GRE tracker

2026-07-24T14:20:26+00:00

[ Upstream commit fe97fd540a03034a780224f24b0b2f0e21c9c763 ]

Move the GRE specific cleanup to nf_conntrack_proto_gre.c to ensure that
the .destroy callback for the pptp helper is still reachable by existing
conntrack entries while pptp module is being removed.

This is a preparation patch, no functional changes are intended.

Signed-off-by: Pablo Neira Ayuso 
Stable-dep-of: 979c13114c0b ("netfilter: nf_conntrack_expect: store master_tuple in expectation")
Signed-off-by: Sasha Levin

netfilter: nf_conntrack_helper: dynamically allocate struct nf_conntrack_helper

2026-07-24T14:20:26+00:00

[ Upstream commit 6031487d4e273d7e7c8c7deea5061b7a9aaa9db3 ]

Adapt all existing helpers to use a modified version of
nf_ct_helper_init(), to dynamically allocate struct nf_conntrack_helper.

Allocate expect_policy[] built-in into the helper to ensure this area is
reachable after helper removal since a follow up patch adds refcount to
track use of the nf_conntrack_helper structure from packet path so it
remains around until last reference from ct helper extension is dropped.

Export __nf_conntrack_helper_register() which allows to register
nfnetlink_cthelper dynamically allocated helper. Adapt nfnetlink_cthelper
to use the built-in expect_policy[].

This is a preparation patch to add packet path refcounting to helpers.

Signed-off-by: Pablo Neira Ayuso 
Stable-dep-of: 979c13114c0b ("netfilter: nf_conntrack_expect: store master_tuple in expectation")
Signed-off-by: Sasha Levin

netfilter: nft_meta_bridge: add validate callback for get operations

2026-07-24T14:20:20+00:00

[ Upstream commit bff1c8b49a9cb5c04af20f4e7d43bf4af5863bc6 ]

Blamed commit added NFT_META_BRI_IIFHWADDR to the set validate callback,
yet this is a get operation.

Add a get validate callback and move the NFT_META_BRI_IIFHWADDR key
there.

AFAICS this is harmless, NFT_META_BRI_IIFHWADDR can deal with a NULL
input device and the set handler ignores a NFT_META_BRI_IIFHWADDR
operation, but it allows to read 4 bytes off bridge skb->cb[].

Fixes: cbd2257dc96e ("netfilter: nft_meta_bridge: introduce NFT_META_BRI_IIFHWADDR support")
Signed-off-by: Florian Westphal 
Reviewed-by: Fernando Fernandez Mancera 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them

2026-07-24T14:19:53+00:00

[ Upstream commit 2354e975932dabb06fad239f07a3b68fd1809737 ]

Update nft_dup and nft_fwd to use the nf_dev_xmit_recursion() helpers.
This patch also disables BH when transmitting the skb to address a
possible migration to different CPU leading to imbalanced decrementation
of the recursion counters.

This is modeled after Florian Westphal's dev_xmit_recursion*() API
available since commit 97cdcf37b57e ("net: place xmit recursion in
softnet data") according to its current state in the tree.

Fixes: 1d47b55b36d2 ("netfilter: nft_fwd_netdev: use recursion counter in neigh egress path")
Fixes: f37ad9127039 ("netfilter: nf_dup_netdev: Move the recursion counter struct netdev_xmit")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: conntrack: revert ct extension genid infrastructure

2026-07-24T14:19:33+00:00

[ Upstream commit 35e21a4dccc5c255ba59ccfbfeb4629ed21da972 ]

This infrastructure is not used anymore after moving ct timeout and
helper to use datapath refcount to track object use.

Revert commit c56716c69ce1 ("netfilter: extensions: introduce extension
genid count") this patch disables all ct extensions (leading to NULL)
for unconfirmed conntracks, when this is only targeted at ct helper and
ct timeout. There is also codebase that dereferences the ct extension
without checking for NULL which could lead to crash.

Fixes: c56716c69ce1 ("netfilter: extensions: introduce extension genid count")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin