linux-toradex.git/net/netfilter, branch master

netfilter: flowtable: restore ieee80211 forward path

2026-09-30T07:35:20+00:00

Before commit 871df5007eda ("netfilter: flowtable: bail out if forward
path cannot be discovered"), there was a fallback to set up a forward
path in case .ndo_fill_forward_path fails or DEV_PATH_MTK_WDMA was used.
Such fallback was used by commit d787a3e38f01 ("mac80211: add support
for .ndo_fill_forward_path").

One possibility is to handle DEV_PATH_MTK_WDMA from the flowtable
forward path discovery. However, this is only used internally by drivers
to retrieve mtk_wdma information to set up hardware offload. Felix
decided to use the .fill_forward_path interface for this purpose due to
the lack of a better interface at that time.

Add a new DEV_PATH_IEEE80211 path which is offered if the new ieee80211
flag is set on in the struct net_device_path_ctx to restore the
flowtable with a ieee80211 netdevice. Handle this new DEV_PATH_IEEE80211
path just like DEV_PATH_ETHERNET and DEV_PATH_DSA, ie. this is the last
netdevice in the stack.

This new ieee80211 flag is implicitly unset for mtk_ppe and airoha which
call dev_fill_forward_path() to retrieve a DEV_PATH_MTK_WDMA path.

Fixes: 871df5007eda ("netfilter: flowtable: bail out if forward path cannot be discovered")
Signed-off-by: Pablo Neira Ayuso

netfilter: flowtable: generalize pending status bit

2026-09-30T07:35:20+00:00

Rename NF_FLOW_HW_PENDING to NF_FLOW_PENDING and use it to inhibit the
flowtable GC worker until pending hw offload work has been completed.

Apparently, nf_flow_offload_stats() can schedule work to retrieve stats
while the flow is being removed by GC.

And this bit can also be used in a follow up patch to disable GC until
the flow has been fully added in both directions.

Revert the reordering done in commit d644b23afe1e ("netfilter:
flowtable: publish HW_DEAD after worker is done") to prevent a race
between GC and hw offload handler.

Fixes: 2c8897953f3b ("netfilter: flowtable: Add pending bit for offload work")
Signed-off-by: Pablo Neira Ayuso

netfilter: bpf: reject invalid NAT manipulation types

2026-09-30T07:35:20+00:00

As bpf_ct_set_nat_info() is not validating the NAT manipulation type a
wrong value can be passed directly to nf_nat_setup_info(). This triggers
the WARN_ON() at nf_nat_setup_info() and if panic_on_warn isn't set,
then IPS_SRC_NAT_DONE is set without adding nat_bysource and conntrack
cleanup tries to unlink an uninitialized hlist node.

Fix this by checking that NAT manipulation type is correct before
calling nf_nat_setup_info(). In addition, if the WARN_ON is hit, return
NF_DROP instead of continuing with the processing to avoid similar
situations in the future.

Reported-by: VEGA 
Fixes: 0fabd2aa199f ("net: netfilter: add bpf_ct_set_nat_info kfunc helper")
Signed-off-by: Fernando Fernandez Mancera 
Signed-off-by: Pablo Neira Ayuso

netfilter: nft_set_rbtree: skip transaction elements during GC

2026-09-30T07:35:20+00:00

Since nft_set_commit_update() runs set commit callbacks before processing
NEWSETELEM transactions, nft_rbtree_gc_scan() can observe elements added by
the transaction being committed.

The scan records an interval end in rbe_end without checking the element's
transaction state. A later, unrelated expired start then moves both
elements to the expired list. The synchronous GC queue can free the new end
element before the transaction subsequently activates it, causing a
use-after-free.

Only consider elements that are fully active in both generations. This
keeps transaction-state elements out of the GC scan and preserves interval
pairing across skipped elements.

KASAN reports:

  BUG: KASAN: slab-use-after-free in nft_setelem_activate
  nft_setelem_activate net/netfilter/nf_tables_api.c:7047
  nf_tables_commit net/netfilter/nf_tables_api.c:11137

  Allocated by task 130:
  nft_set_elem_init net/netfilter/nf_tables_api.c:6794
  nft_add_set_elem net/netfilter/nf_tables_api.c:7523

  Freed by task 130:
  nft_trans_gc_trans_free net/netfilter/nf_tables_api.c:10506
  rcu_core kernel/rcu/tree.c:2919

Fixes: 1e3b9e1c77fe ("netfilter: nf_tables: call set ops .commit when building new ruleset blob")
Reported-by: 
Assisted-by: LLM
Signed-off-by: Weiming Shi 
Signed-off-by: Pablo Neira Ayuso

ipvs: filter some flags received in the backup server

2026-09-30T07:35:20+00:00

While the IPVS SYNC protocol is not secure by design
we can still protect the backup server from messages that
can wreak havoc.

This commit addresses problems from received connection flags
or their combinations. We now drop messages as follows:

1. the NO_CPORT+TEMPLATE combination allows lookups for normal
connections to hit template which can break in many ways.
While the master does not sync connections with NO_CPORT flag,
i.e. before they are established, we still accept NO_CPORT
without TEMPLATE.

2. ONE_PACKET: it is not sent by master, so we do not
expect it in backup. Before now it was ignored by
IP_VS_CONN_F_BACKUP_MASK for protocol v1 while protocol
v0 created connections that are not hashed and dropped
immediately. Better to apply the IP_VS_CONN_F_BACKUP_MASK
also to the flags from v0 messages for consistency with v1.

Fixes: 87375ab47cd0 ("[IPVS]: ip_vs_ftp breaks connections using persistence")
Signed-off-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso

ipvs: do not create invisible templates

2026-09-30T07:35:20+00:00

The IP_VS_CONN_F_ONE_PACKET flag was implemented for normal
connections. When conn template inherits this flag from
dest->conn_flags it will not be hashed. As result, we will
create new template for every new normal connection.

Fix it to allow one template to be used by many normal
connections.

Fixes: 26ec037f9841 ("IPVS: one-packet scheduling")
Link: https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260916231652.127456-1-pablo%40netfilter.org
Signed-off-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso

ipvs: bound LBLCR and LBLC cache growth

2026-09-30T07:35:20+00:00

ip_vs_lblcr_new() and ip_vs_lblc_new() create cache entries for
every previously unseen destination address. The table max_size only
tells the periodic collector to reclaim entries after the cache has
already exceeded the limit. It does not reclaim entries that the
attacker continues to use.

Reject new cache entries once either table reaches max_size * 3 / 2.
The extra headroom lets the periodic collector catch up while the
existing scheduler fallback continues to use the selected destination
when cache creation fails. New traffic therefore stays serviceable
without growing the tables further.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reported-by: Vega 
Suggested-by: Julian Anastasov 
Signed-off-by: Zhiling Zou 
Acked-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso

ipvs: fix missing counter decrement in lblc

2026-09-30T07:35:20+00:00

LBLC may delete cache entries for destinations that are
removed or overloaded and replace them with available ones.
But ip_vs_lblc_new() forgets to decrement the tbl->entries
counter after calling ip_vs_lblc_del(). This can lead to
increased shrinking of the cache with every new garbage
collection.

Fixes: 2f3d771a35fe ("ipvs: do not use dest after ip_vs_dest_put in LBLC")
Link: https://sashiko.dev/#/patchset/0bdd5abe9968ded7ca2b9cb6844ba83d94cc8d53.1787318053.git.zhilinz%40nebusec.ai
Signed-off-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso

netfilter: nft_flow_offload: drop flowtable reference on init error path

2026-09-30T07:35:20+00:00

nft_flow_offload_init() bumps the flowtable use count with
nft_use_inc() before calling nf_ct_netns_get().  When the latter
fails, the error is returned as-is and the reference is leaked.

The upper layers do not balance it either: nf_tables_newexpr()
clears expr->ops when the expression init callback fails, so the
nft_expr_more() iteration in nft_rule_expr_deactivate() and
nf_tables_rule_destroy() stops right before the failed expression
and its ->destroy callback, which would drop the reference, never
runs.

Each failed rule addition therefore leaks one flowtable reference
and the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE
keeps reporting -EBUSY even though no rule references it.

Save the nf_ct_netns_get() return value and undo the nft_use_inc()
when it fails, restoring the inc/dec pairing within
nft_flow_offload_init() itself.

Fixes: a3c90f7a2323 ("netfilter: nf_tables: flow offload expression")
Reported-by: TencentOS Corvus AI 
Cc: stable@vger.kernel.org
Assisted-by: CodeBuddy:Kimi-K3
Signed-off-by: Aohan Mei 
Signed-off-by: Pablo Neira Ayuso

netfilter: ipset: do not update comments from kernel-side adds

2026-09-27T20:38:47+00:00

'Fixes' commit stopped calling ip_set_init_comment() for hash types
from kernel-side-adds (xtables .. -j SET).  ip_set_init_comment() says:

   "The kadt functions don't use the comment extensions in any way."

But bitmap set type calls the function from kadt cb too.

While this appears to be safe (serialized via the set spinlock), it seems
better to not call the init function either, least of all to keep
behaviour consistent.

ip_set_list calls ip_set_init_comment() only from uadt cb, it can be
kept as-is.

This was triggered by yet another LLM review, hinting that the existing
rcu_dereference_protected() cannot be downgraded to only check if the
nfnl mutex is held.

Fixes: f30415929be8 ("netfilter: ipset: do not update comments from kernel-side hash adds")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso