Pull networking fixes from Paolo Abeni:
 "Including fixes from netfilter and batman-adv.

  Current release - new code bugs:

   - netfilter: cthelper: cap to maximum number of expectation per master

  Previous releases - regressions:

   - netpoll: fix a use-after-free on shutdown path

   - tcp: restore RCU grace period in tcp_ao_destroy_sock

   - ipv6: fix NULL deref in fib6_walk_continiue() on multi-batch dump

   - batman-adv: dat: ensure accessible eth_hdr proto field

   - eth:
      - virtio_net: disable cb when NAPI is busy-polled
      - lan743x: Initialize eth_syslock spinlock before use

  Previous releases - always broken:

   - netfilter:
      - nft_set_pipapo: don't leak bad clone into future transaction

   - sched:
      - sch_teql: Introduce slaves_lock to avoid race condition and UAF
      - replace direct dequeue call with peek and qdisc_dequeue_peeked

   - sctp: add INIT verification after cookie unpacking

   - tipc: fix out-of-bounds read in broadcast Gap ACK blocks

   - seg6: validate SRH length before reading fixed fields

   - eth:
      - mlx5e: fix use-after-free of metadata_dst on RX SC delete
      - enetc: check the number of BDs needed for xdp_frame
      - fbnic: don't cache shinfo across skb realloc"

* tag 'net-7.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (58 commits)
  net/mlx5: HWS, fix matcher leak on resize target setup failure
  net/sched: hhf: clear heavy-hitter state on reset
  net/sched: dualpi2: clear stale classification on filter miss
  net/sched: act_bpf: use rcu_dereference_bh() to read the filter
  selftests: drv-net: tso: don't touch dangerous feature bits
  cxgb4: Fix decode strings dump for T6 adapters
  virtio_net: disable cb when NAPI is busy-polled
  sctp: fix addr_wq_timer race in sctp_free_addr_wq()
  selftests: net: bump default cmd() timeout to 20 seconds
  bridge: stp: Fix a potential use-after-free when deleting a bridge
  net/sched: sch_teql: Introduce slaves_lock to avoid race condition and UAF
  net: gianfar: dispose irq mappings on probe failure and device removal
  net: lan743x: Initialize eth_syslock spinlock before use
  net: libwx: fix VMDQ mask for 1-queue mode
  net: airoha: fix max receive size configuration
  fsl/fman: Free init resources on KeyGen failure in fman_init()
  netfilter: nftables: restrict checkum update offset
  netfilter: nftables: restrict linklayer and network header writes
  netfilter: nfnetlink_queue: restrict writes to network header
  netfilter: nft_fib: reject fib expression on the netdev egress hook
  ...

After previous patch, writes to network header are restricted.
However, there is another way to manipulate the l3 header: The
checksum update function.

Restrict this for network header writes, only the ipv4 header is
allowed.  This needs run-time checks because BRIDGE, INET, NETDEV
families can carry l3 headers other than IP.

checksum updates to the udp/tcp (l4) headers are not restricted.

Signed-off-by: Florian Westphal <fw@strlen.de>

Don't permit arbitrary writes to linklayer and network header data.
Several spots in network stack trust header validation performed in
ipv4/ipv6 before PRE_ROUTING hook.

For linklayer, allow writes for netdev ingress. For other hooks, only
allow link layer writes that do not spill into network header.

For network header, check the offset/length combinations:
 - changing dscp requires store at offset 0 for checsum fixups, so
 make sure ip version + length field isn't altered.
 - ip6 dscp starts directly after the version field, so make sure it
   remains 6.

Several of these checks could already be done at rule insertion time.
Risk is that this might cause ruleset load failures for existing
rulesets. With this change such writes are silently skipped and packet
passes unchanged.

Transport and inner header bases are not checked / restricted.

Signed-off-by: Florian Westphal <fw@strlen.de>

nfnetlink_queue doesn't allow selective replacements of some part of the
payload, only complete replacement.
If the new data is shorter, skb is trimmed, otherwise expanded.

Add minimal validation of the new ip/ipv6 header.  Check total len
matches skb length.  Disallow ip option modifications.

IPv6 extension headers are also disabled.
IP options and exthdrs could be allowed later after validation pass or
ip option recompile.

Transport header is not checked.

Bridge modifications are rejected.  Given userspace doesn't even receive
L2 headers, use is limited and I don't think there are any users of
bridge nfnetlink_queue, let alone users that modifiy payload.

Arp isn't supported at all.

Signed-off-by: Florian Westphal <fw@strlen.de>

A fib expression in a netdev egress base chain dereferences nft_in(pkt),
NULL on the transmit path, causing a NULL pointer dereference at eval.
nft_fib_validate() masks the hook with NF_INET_* values, but netdev hook
numbers are a separate enum that aliases them (NF_NETDEV_EGRESS ==
NF_INET_LOCAL_IN), so an egress chain passes validation and then faults.

Add nft_fib_netdev_validate() that limits each result/flag to the netdev
hook where the device it reads exists: the input-device cases (OIF,
OIFNAME, ADDRTYPE with F_IIF) to ingress, the output-device case (ADDRTYPE
with F_OIF) to egress, ADDRTYPE with no device flag to both. Also restrict
nft_fib_validate() to NFPROTO_IPV4/IPV6/INET so its NF_INET_* masks are
not applied to another family's hooks.

Fixes: 42df6e1d221d ("netfilter: Introduce egress hook")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/netfilter-devel/ajxsjcDOnwllMfoR@strlen.de/
Signed-off-by: Theodor Arsenij Larionov-Trichkine <theodorlarionov@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>

If userspace helper policy updates sets maximum number of expectation to
zero, cap it to NF_CT_EXPECT_MAX_CNT (255) on updates too.

Fixes: 397c8300972f ("netfilter: nf_conntrack_helper: cap maximum number of expectation at helper registration")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>

tc ingress and openvswitch do not guarantee routing information to be
available. These subsystems use the conntrack helper infrastructure, and
the SIP helper relies on the skb_dst() to be present if
sip_external_media is set to 1 (which is disabled by default as a module
parameter).

This effectively disables the sip_external_media toggle for these
subsystems without resulting in a crash.

Fixes: cae3a2627520 ("openvswitch: Allow attaching helpers to ct action")
Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Cc: stable@vger.kernel.org
Reported-by: Ren Wei <n05ec@lzu.edu.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>

The release path of ip_set_dump_do() and ip_set_dump_done() read
inst->ip_set_list via ip_set_ref_netlink(), a plain rcu_dereference_raw()
of the array pointer. These run from netlink_recvmsg() without the nfnl
mutex and without an RCU read-side critical section.

A concurrent ip_set_create() can grow the array: it publishes the new
array, calls synchronize_net() and then kvfree()s the old one. Since the
dump paths read the array outside any RCU reader, synchronize_net() does
not wait for them and the old array can be freed while they still index
into it, causing a use-after-free.

The dumped set itself stays pinned via set->ref_netlink, so only the
array load needs protecting. Take rcu_read_lock() around it, matching
ip_set_get_byname() and __ip_set_put_byindex().

  BUG: KASAN: slab-use-after-free in ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697)
  Read of size 8 at addr ffff88800b5c4018 by task exploit/150
  Call Trace:
   ...
   kasan_report (mm/kasan/report.c:595)
   ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697)
   netlink_dump (net/netlink/af_netlink.c:2325)
   netlink_recvmsg (net/netlink/af_netlink.c:1976)
   sock_recvmsg (net/socket.c:1159)
   __sys_recvfrom (net/socket.c:2315)
   ...
  Oops: general protection fault, probably for non-canonical address ... KASAN NOPTI
  KASAN: maybe wild-memory-access in range [0x02d6...d0-0x02d6...d7]
  RIP: 0010:ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1698)
  Kernel panic - not syncing: Fatal exception

Fixes: 8a02bdd50b2e ("netfilter: ipset: Fix calling ip_set() macro at dumping")
Cc: stable@vger.kernel.org
Reported-by: Weiming Shi <bestswngs@gmail.com>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>

On memory allocation failure the cloned nft_pipapo_match can enter a bad
state:
 - some fields can have their lookup tables resized while others did
   not
 - bits might have been toggled
 - scratch map can be undersized which also means m->bsize_max can be
   lower than what is required

This means that the next insertion in the same batch can trigger
out-of-bounds writes.

Furthermore, a failure in the first can result in the bad clone to
leak into the next transaction because the abort callback is never
executed in this case (the upper layer saw an error and no attempt to
allocate a transactional request was made).

Record a state for the nft_pipapo_match structure:
- NEW (pristine clone)
- MOD (modified clone with good state)
- ERR (potentially bogus content)

Then make it so that deletes and insertions fail when the clone
entered ERR state.

In case the very first insert attempt results in an error, free the
clone right away.

Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Cc: stable@vger.kernel.org
Reported-and-tested-by: Seesee <cjc000013@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>

There are occasional LLM hints wrt. leaking uninitialized data to
userspace via ctnetlink.  Just zero at allocation time,
expectations are not frequently used these days.

Intentionally keeps _init as-is because we could theoretically
support re-init, so add the missing exp->dir there.

Signed-off-by: Florian Westphal <fw@strlen.de>