linux.git/net/netfilter, branch v7.2

Merge tag 'net-7.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-08-13T15:37:26+00:00

Pull networking fixes from Paolo Abeni:
 "Including fixes from netfilter.

  There is a known WiFi/mt76 regression, waiting for a complete fix that
  should land soonish.

  Previous releases - regressions:

   - tcp: fix icsk_ack.ato bitfield overflow

   - af_unix: Unlink scc_entry in unix_del_edge()

   - ipv4: fix use-after-free in fib_nhc_update_mtu()

   - netfilter:
      - ipset: fix refcount race between list:set GC and swap
      - nf_tables_offload: suppress WARN_ON_ONCE for ENOMEM in abort
        path

   - sched: act_ct: fix sk_buff leak when the header checks reject a
     packet

   - sctp: clear new_transport when removing a peer

   - dibs: correct freeing of dmb_clientid_arr

   - ovpn: fix NULL dereference when killing missing key

   - eth:
      - veth: fix queue index used to wake the peer txq in veth_poll
      - ngbe: fix NULL pointer dereference in non-MSI-X interrupt
        enabling
      - gve: fix zero-length skb frag with header-split

  Previous releases - always broken:

   - core: fix skb length accounting after generic XDP frag adjustment

   - af_packet: don't send zero-byte data in tpacket_snd().

   - eth:
      - bnxt: avoid deadlock when canceling IRQ affinity notifier
      - ipvlan: inherit needed_headroom and needed_tailroom from
        phy_dev"

* tag 'net-7.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (55 commits)
  l2tp: fix tunnel and session refcount leak on seq_file release
  net/sched: cls_bpf: reject dev-bound programs bound to a different device
  sctp: fix use-after-free of cached ASCONF chunk
  net: ethernet: ti: am65-cpsw-nuss: Fix port_id extraction from SRC TAG
  sctp: clear new_transport when removing a peer
  net/dibs: Correct freeing of dmb_clientid_arr
  net/sched: cls_u32: skip hash tables in u32_bind_class()
  gve: fix NULL dereference due to missing ptp adjfine
  gve: fix zero-length skb frag with header-split
  net/sched: act_api: fix TOCTOU NULL deref on a->goto_chain
  af_packet: Don't send zero-byte data in tpacket_snd().
  tipc: read le->link under the node lock in tipc_node_link_down()
  selftests: tls: cover splice after a failed decrypt
  net/tls: Fail tls_sw_splice_read() after a failed async decrypt
  net: ngbe: fix NULL pointer dereference in non-MSI-X interrupt enabling
  net: tap: fix wrong transport_header when sending VLAN-tagged frame
  net: packet: fix wrong transport_header when sending VLAN-tagged frame
  vxlan: do not arm the ageing timer on a device that is down
  ipv4: fix use-after-free in fib_nhc_update_mtu()
  NTB: ntb_netdev: Preserve RX queue depth on allocation failure
  ...

netfilter: ipset: let destroy callbacks adjust ext mem size

2026-08-10T18:28:25+00:00

For bitmap this change makes no difference, because destructors are
called synchronously.

List type however calls them via call_rcu() so accounting decrement can
happen after list_set_flush() set ext_size to 0.

'set->elements = 0' can be removed for the same reason in the list type
case, it calls 'set->elements--' for each element.

Fixes: 9e41f26a505c ("netfilter: ipset: Count non-static extension memory for userspace")
Suggested-by: Jozsef Kadlecsik 
Signed-off-by: Florian Westphal 
Acked-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso

netfilter: ipset: fix list type element drift bug

2026-08-10T18:28:15+00:00

If list_set_uadd() calls list_set_replace() to swap an expired entry,
the element count remains the same, therefore the increment must be elided.

Fixes: 702b71e7c666 ("netfilter: ipset: Add element count to all set types header")
Link: https://sashiko.dev/#/patchset/20260806101947.2802-1-fw%40strlen.de
Signed-off-by: Florian Westphal 
Acked-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso

netfilter: flowtable: publish GC-visible tuple last

2026-08-10T18:27:50+00:00

nf_flow_table_iterate() only treats original-direction tuple nodes as
owning entries. Publishing the original node first lets GC observe and
free a flow while flow_offload_add() is still inserting the reply node.
Publish the reply node first and the original node last so GC never
sees a partially installed flow.

KASAN can trigger slab-use-after-free read and write reports in the
flowtable/rhashtable path (rht_deferred_worker, jhash, flow_offload_del,
flow_offload_lookup, etc.).

Fixes: ac2a66665e23 ("netfilter: add generic flow table infrastructure")
Signed-off-by: Jérémy Jean 
Assisted-by: Codex:gpt-5
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables_offload: suppress WARN_ON_ONCE for ENOMEM in abort path

2026-08-10T18:27:29+00:00

In nft_flow_rule_offload_abort(), WARN_ON_ONCE(err) is triggered on every
error during rollback, including -ENOMEM. Memory allocation failures are
expected under low-memory conditions and do not indicate a kernel bug.

Trace for example:
nft_flow_offload_chain() // FLOW_BLOCK_BIND
  nft_flow_block_chain()
    nft_chain_offload_cmd()
      nft_block_offload_cmd()
        ->ndo_setup_tc()
        nsim_setup_tc()
          flow_block_cb_setup_simple()
            flow_block_cb_alloc() // fails to -ENOMEM

The warning was reproduced on the 5.10 stable kernel under memory pressure
via fault injection, but the underlying bug exists in mainline as well,
as demonstrated by the ENOMEM trace above. The following splat was
triggered during nf_tables transaction processing:

WARNING: CPU: 0 PID: 8567 at net/netfilter/nf_tables_offload.c:532 nft_flow_rule_offload_abort net/netfilter/nf_tables_offload.c:532 [inline]
WARNING: CPU: 0 PID: 8567 at net/netfilter/nf_tables_offload.c:532 nft_flow_rule_offload_commit+0x971/0xcd0 net/netfilter/nf_tables_offload.c:591
Modules linked in:
CPU: 0 PID: 8567 Comm: syz-executor.0 Not tainted 5.10.260-syzkaller #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:nft_flow_rule_offload_abort net/netfilter/nf_tables_offload.c:532 [inline]
RIP: 0010:nft_flow_rule_offload_commit+0x971/0xcd0 net/netfilter/nf_tables_offload.c:591
Call Trace:
 nf_tables_commit+0x3bd/0x4bd0 net/netfilter/nf_tables_api.c:8604
 nfnetlink_rcv_batch+0xb1e/0x1f20 net/netfilter/nfnetlink.c:509
 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:579 [inline]
 nfnetlink_rcv+0x3b3/0x420 net/netfilter/nfnetlink.c:597
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x6cd/0xa00 net/netfilter/af_netlink.c:1340
 netlink_sendmsg+0x906/0xe10 net/netfilter/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 __sock_sendmsg+0x155/0x190 net/socket.c:663
 ____sys_sendmsg+0x705/0x870 net/socket.c:2379
 ___sys_sendmsg+0x100/0x170 net/socket.c:2433
 __sys_sendmsg+0xe9/0x1c0 net/socket.c:2462
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x67/0xd1

Change the condition to WARN_ON_ONCE(err && err != -ENOMEM) so that
warnings are only emitted for unexpected errors. This aligns with the
common kernel practice of not warning on -ENOMEM.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 63b48c73ff56 ("netfilter: nf_tables_offload: undo updates if transaction fails")
Signed-off-by: Alexey Velichayshiy 
Signed-off-by: Pablo Neira Ayuso

ipvs: revalidate ihl to prevent out-of-bounds access

2026-08-10T18:27:15+00:00

While the outer IP header is already pulled into the skb head,
we must be careful and revalidate the embedded headers after
reading them from the skb frags to prevent out-of-bounds
access.

One such place reported by Sashiko is ip_vs_nat_icmp() where
local process can change the ihl field and after
skb_ensure_writable() we can see larger value which is a
problem for the ip_send_check(cih) calls.

Add check to drop the packet if the ihl field is changed.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://sashiko.dev/#/patchset/20260730183506.87473-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso

ipvs: clear IPv4 options after rebasing tunnel ICMP errors

2026-08-10T18:27:07+00:00

ip_vs_in_icmp() rebases an skb from the outer ICMP packet to the
quoted original request before passing it to icmp_send(). However,
IPCB(skb)->opt still describes the outer IPv4 header.

A timestamp option in the outer header can therefore leave an offset
that points into the quoted transport header after the rebase.
__ip_options_echo() treats a byte at that stale location as the option
length and copies it into the fixed-size option storage on the
__icmp_send() stack, causing a stack out-of-bounds write.

Clear the stale option metadata after resetting the network header.
Keep the remaining control block fields, including the ingress
interface used by the ICMP response path.

Fixes: f2edb9f7706d ("ipvs: implement passive PMTUD for IPIP packets")
Cc: stable@vger.kernel.org
Assisted-by: Codex:gpt-5.6-sol Codex:gpt-5.5-cyber
Signed-off-by: Kyle Zeng 
Co-developed-by: David Lee 
Signed-off-by: David Lee 
Acked-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso

netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state

2026-08-10T18:26:37+00:00

sashiko reports: "nfnl_log_net_exit() calls nf_log_unset(), which
clears the logger pointer without an RCU grace period.  Immediately after,
ops_free_list() frees the per-net state while concurrent packets might
still be executing nf_log_packet() under rcu_read_lock()."

Clear the pointer via .pre_exit to make sure rcu readers have completed
before pernet storage is free'd.  The change in nf_log_syslog.c is only
done for consistency: it doesn't use pernet data.

Link: https://sashiko.dev/#/patchset/20260731151806.849724-1-pablo%40netfilter.org
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_conntrack: defer invalid log until after unlock

2026-08-10T18:25:56+00:00

TCP and SCTP conntrack paths can emit invalid-packet logs while ct->lock
is still held.

When invalid logging is routed to nfnetlink_log and conntrack export is
enabled, the log path can re-enter conntrack netlink glue and dump the
same conntrack again. Protocol attribute dumping may take ct->lock, so
logging while holding that lock can deadlock.

Defer the TCP invalid logs by storing only the minimal log context while
ct->lock is held and emitting the log after unlocking. Also make the TCP
timeout-lowering invalid path return whether a log is needed, then emit
that log after unlocking.

Do the same for the SCTP invalid state-transition log that can be reached
while ct->lock is held.

Add a lockdep assertion to nf_ct_l4proto_log_invalid() so future callers
that log invalid conntracks while holding ct->lock are caught outside TCP
and SCTP as well.

Fixes: 628d694344a0 ("netfilter: conntrack: reduce timeout when receiving out-of-window fin or rst")
Fixes: d9a6f0d0df18 ("netfilter: conntrack: prepare tcp_in_window for ternary return value")
Fixes: f71cb8f45d09 ("netfilter: conntrack: sctp: use nf log infrastructure for invalid packets")
Cc: stable@vger.kernel.org
Reported-by: Vega 
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zihan Xi 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

ipvs: separate destination availability state

2026-08-10T18:23:35+00:00

IPVS configuration paths update destination availability while connection
accounting updates destination overload state. The two independent states
share dest->flags, so their read-modify-write updates can race and lose one
another.

Keep OVERLOAD in flags, where the preceding patch serializes its updates
with dst_lock, and move AVAILABLE to cflags. This keeps configuration-
controlled availability out of the scheduler hot cacheline until a
scheduler needs to check it. It also prevents availability updates from
clobbering overload state.

The destination status bits are not exposed through the IPVS sockopt or
netlink interfaces, so keep their definitions in the internal IPVS header.

Readers can still observe stale destination state; this does not provide a
cross-field snapshot.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reported-by: Yizhou Zhao 
Reported-by: Yuxiang Yang 
Reported-by: Ao Wang 
Reported-by: Xuewei Feng 
Reported-by: Qi Li 
Reported-by: Ke Xu 
Link: https://lore.kernel.org/all/8913381c-1e02-35c7-0ec4-61de5a12fd35@ssi.bg/
Assisted-by: Claude-Code:GLM-5.2
Suggested-by: Julian Anastasov 
Signed-off-by: Yizhou Zhao 
Acked-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso