Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too.
While ipv4 tunnel headroom adjustment growth was limited in
commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"),
ipv6 tunnel yet increases the headroom without any ceiling.

Reflect ipv4 tunnel headroom adjustment limit on ipv6 version.

Credits to Francesco Ruggeri, who was originally debugging this issue
and wrote local Arista-specific patch and a reproducer.

Fixes: 8eb30be0352d ("ipv6: Create ip6_tnl_xmit")
Cc: Florian Westphal <fw@strlen.de>
Cc: Francesco Ruggeri <fruggeri05@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://patch.msgid.link/20251009-ip6_tunnel-headroom-v2-1-8e4dbd8f7e35@arista.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Rx path may be passing around unreferenced sockets, which means
that skb_set_owner_edemux() may not set skb->sk and PSP will crash:

  KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
  RIP: 0010:psp_reply_set_decrypted (./include/net/psp/functions.h:132 net/psp/psp_sock.c:287)
    tcp_v6_send_response.constprop.0 (net/ipv6/tcp_ipv6.c:979)
    tcp_v6_send_reset (net/ipv6/tcp_ipv6.c:1140 (discriminator 1))
    tcp_v6_do_rcv (net/ipv6/tcp_ipv6.c:1683)
    tcp_v6_rcv (net/ipv6/tcp_ipv6.c:1912)

Fixes: 659a2899a57d ("tcp: add datapath logic for PSP with inline key exchange")
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251001022426.2592750-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull networking updates from Paolo Abeni:
 "Core & protocols:

   - Improve drop account scalability on NUMA hosts for RAW and UDP
     sockets and the backlog, almost doubling the Pps capacity under DoS

   - Optimize the UDP RX performance under stress, reducing contention,
     revisiting the binary layout of the involved data structs and
     implementing NUMA-aware locking. This improves UDP RX performance
     by an additional 50%, even more under extreme conditions

   - Add support for PSP encryption of TCP connections; this mechanism
     has some similarities with IPsec and TLS, but offers superior HW
     offloads capabilities

   - Ongoing work to support Accurate ECN for TCP. AccECN allows more
     than one congestion notification signal per RTT and is a building
     block for Low Latency, Low Loss, and Scalable Throughput (L4S)

   - Reorganize the TCP socket binary layout for data locality, reducing
     the number of touched cachelines in the fastpath

   - Refactor skb deferral free to better scale on large multi-NUMA
     hosts, this improves TCP and UDP RX performances significantly on
     such HW

   - Increase the default socket memory buffer limits from 256K to 4M to
     better fit modern link speeds

   - Improve handling of setups with a large number of nexthop, making
     dump operating scaling linearly and avoiding unneeded
     synchronize_rcu() on delete

   - Improve bridge handling of VLAN FDB, storing a single entry per
     bridge instead of one entry per port; this makes the dump order of
     magnitude faster on large switches

   - Restore IP ID correctly for encapsulated packets at GSO
     segmentation time, allowing GRO to merge packets in more scenarios

   - Improve netfilter matching performance on large sets

   - Improve MPTCP receive path performance by leveraging recently
     introduced core infrastructure (skb deferral free) and adopting
     recent TCP autotuning changes

   - Allow bridges to redirect to a backup port when the bridge port is
     administratively down

   - Introduce MPTCP 'laminar' endpoint that con be used only once per
     connection and simplify common MPTCP setups

   - Add RCU safety to dst->dev, closing a lot of possible races

   - A significant crypto library API for SCTP, MPTCP and IPv6 SR,
     reducing code duplication

   - Supports pulling data from an skb frag into the linear area of an
     XDP buffer

  Things we sprinkled into general kernel code:

   - Generate netlink documentation from YAML using an integrated YAML
     parser

  Driver API:

   - Support using IPv6 Flow Label in Rx hash computation and RSS queue
     selection

   - Introduce API for fetching the DMA device for a given queue,
     allowing TCP zerocopy RX on more H/W setups

   - Make XDP helpers compatible with unreadable memory, allowing more
     easily building DevMem-enabled drivers with a unified XDP/skbs
     datapath

   - Add a new dedicated ethtool callback enabling drivers to provide
     the number of RX rings directly, improving efficiency and clarity
     in RX ring queries and RSS configuration

   - Introduce a burst period for the health reporter, allowing better
     handling of multiple errors due to the same root cause

   - Support for DPLL phase offset exponential moving average,
     controlling the average smoothing factor

  Device drivers:

   - Add a new Huawei driver for 3rd gen NIC (hinic3)

   - Add a new SpacemiT driver for K1 ethernet MAC

   - Add a generic abstraction for shared memory communication
     devices (dibps)

   - Ethernet high-speed NICs:
      - nVidia/Mellanox:
         - Use multiple per-queue doorbell, to avoid MMIO contention
           issues
         - support adjacent functions, allowing them to delegate their
           SR-IOV VFs to sibling PFs
         - support RSS for IPSec offload
         - support exposing raw cycle counters in PTP and mlx5
         - support for disabling host PFs.
      - Intel (100G, ice, idpf):
         - ice: support for SRIOV VFs over an Active-Active link
           aggregate
         - ice: support for firmware logging via debugfs
         - ice: support for Earliest TxTime First (ETF) hardware offload
         - idpf: support basic XDP functionalities and XSk
      - Broadcom (bnxt):
         - support Hyper-V VF ID
         - dynamic SRIOV resource allocations for RoCE
      - Meta (fbnic):
         - support queue API, zero-copy Rx and Tx
         - support basic XDP functionalities
         - devlink health support for FW crashes and OTP mem corruptions
         - expand hardware stats coverage to FEC, PHY, and Pause
      - Wangxun:
         - support ethtool coalesce options
         - support for multiple RSS contexts

   - Ethernet virtual:
      - Macsec:
         - replace custom netlink attribute checks with policy-level
           checks
      - Bonding:
         - support aggregator selection based on port priority
      - Microsoft vNIC:
         - use page pool fragments for RX buffers instead of full pages
           to improve memory efficiency

   - Ethernet NICs consumer, and embedded:
      - Qualcomm: support Ethernet function for IPQ9574 SoC
      - Airoha: implement wlan offloading via NPU
      - Freescale
         - enetc: add NETC timer PTP driver and add PTP support
         - fec: enable the Jumbo frame support for i.MX8QM
      - Renesas (R-Car S4):
         - support HW offloading for layer 2 switching
         - support for RZ/{T2H, N2H} SoCs
      - Cadence (macb): support TAPRIO traffic scheduling
      - TI:
         - support for Gigabit ICSS ethernet SoC (icssm-prueth)
      - Synopsys (stmmac): a lot of cleanups

   - Ethernet PHYs:
      - Support 10g-qxgmi phy-mode for AQR412C, Felix DSA and Lynx PCS
        driver
      - Support bcm63268 GPHY power control
      - Support for Micrel lan8842 PHY and PTP
      - Support for Aquantia AQR412 and AQR115

   - CAN:
      - a large CAN-XL preparation work
      - reorganize raw_sock and uniqframe struct to minimize memory
        usage
      - rcar_canfd: update the CAN-FD handling

   - WiFi:
      - extended Neighbor Awareness Networking (NAN) support
      - S1G channel representation cleanup
      - improve S1G support

   - WiFi drivers:
      - Intel (iwlwifi):
         - major refactor and cleanup
      - Broadcom (brcm80211):
         - support for AP isolation
      - RealTek (rtw88/89) rtw88/89:
         - preparation work for RTL8922DE support
      - MediaTek (mt76):
         - HW restart improvements
         - MLO support
      - Qualcomm/Atheros (ath10k):
         - GTK rekey fixes

   - Bluetooth drivers:
      - btusb: support for several new IDs for MT7925
      - btintel: support for BlazarIW core
      - btintel_pcie: support for _suspend() / _resume()
      - btintel_pcie: support for Scorpious, Panther Lake-H484 IDs"

* tag 'net-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1536 commits)
  net: stmmac: Add support for Allwinner A523 GMAC200
  dt-bindings: net: sun8i-emac: Add A523 GMAC200 compatible
  Revert "Documentation: net: add flow control guide and document ethtool API"
  octeontx2-pf: fix bitmap leak
  octeontx2-vf: fix bitmap leak
  net/mlx5e: Use extack in set rxfh callback
  net/mlx5e: Introduce mlx5e_rss_params for RSS configuration
  net/mlx5e: Introduce mlx5e_rss_init_params
  net/mlx5e: Remove unused mdev param from RSS indir init
  net/mlx5: Improve QoS error messages with actual depth values
  net/mlx5e: Prevent entering switchdev mode with inconsistent netns
  net/mlx5: HWS, Generalize complex matchers
  net/mlx5: Improve write-combining test reliability for ARM64 Grace CPUs
  selftests/net: add tcp_port_share to .gitignore
  Revert "net/mlx5e: Update and set Xon/Xoff upon MTU set"
  net: add NUMA awareness to skb_attempt_defer_free()
  net: use llist for sd->defer_list
  net: make softnet_data.defer_count an atomic
  selftests: drv-net: psp: add tests for destroying devices
  selftests: drv-net: psp: add test for auto-adjusting TCP MSS
  ...

Cross-merge networking fixes after downstream PR (net-6.17-rc8).

Conflicts:

tools/testing/selftests/drivers/net/bonding/Makefile
  87951b566446 selftests: bonding: add test for passive LACP mode
  c2377f1763e9 selftests: bonding: add test for LACP actor port priority

Adjacent changes:

drivers/net/ethernet/cadence/macb.h
  fca3dc859b20 net: macb: remove illusion about TBQPH/RBQPH being per-queue
  89934dbf169e net: macb: Add TAPRIO traffic scheduling support

drivers/net/ethernet/cadence/macb_main.c
  fca3dc859b20 net: macb: remove illusion about TBQPH/RBQPH being per-queue
  89934dbf169e net: macb: Add TAPRIO traffic scheduling support

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Pull bpf updates from Alexei Starovoitov:

 - Support pulling non-linear xdp data with bpf_xdp_pull_data() kfunc
   (Amery Hung)

   Applied as a stable branch in bpf-next and net-next trees.

 - Support reading skb metadata via bpf_dynptr (Jakub Sitnicki)

   Also a stable branch in bpf-next and net-next trees.

 - Enforce expected_attach_type for tailcall compatibility (Daniel
   Borkmann)

 - Replace path-sensitive with path-insensitive live stack analysis in
   the verifier (Eduard Zingerman)

   This is a significant change in the verification logic. More details,
   motivation, long term plans are in the cover letter/merge commit.

 - Support signed BPF programs (KP Singh)

   This is another major feature that took years to materialize.

   Algorithm details are in the cover letter/marge commit

 - Add support for may_goto instruction to s390 JIT (Ilya Leoshkevich)

 - Add support for may_goto instruction to arm64 JIT (Puranjay Mohan)

 - Fix USDT SIB argument handling in libbpf (Jiawei Zhao)

 - Allow uprobe-bpf program to change context registers (Jiri Olsa)

 - Support signed loads from BPF arena (Kumar Kartikeya Dwivedi and
   Puranjay Mohan)

 - Allow access to union arguments in tracing programs (Leon Hwang)

 - Optimize rcu_read_lock() + migrate_disable() combination where it's
   used in BPF subsystem (Menglong Dong)

 - Introduce bpf_task_work_schedule*() kfuncs to schedule deferred
   execution of BPF callback in the context of a specific task using the
   kernel’s task_work infrastructure (Mykyta Yatsenko)

 - Enforce RCU protection for KF_RCU_PROTECTED kfuncs (Kumar Kartikeya
   Dwivedi)

 - Add stress test for rqspinlock in NMI (Kumar Kartikeya Dwivedi)

 - Improve the precision of tnum multiplier verifier operation
   (Nandakumar Edamana)

 - Use tnums to improve is_branch_taken() logic (Paul Chaignon)

 - Add support for atomic operations in arena in riscv JIT (Pu Lehui)

 - Report arena faults to BPF error stream (Puranjay Mohan)

 - Search for tracefs at /sys/kernel/tracing first in bpftool (Quentin
   Monnet)

 - Add bpf_strcasecmp() kfunc (Rong Tao)

 - Support lookup_and_delete_elem command in BPF_MAP_STACK_TRACE (Tao
   Chen)

* tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (197 commits)
  libbpf: Replace AF_ALG with open coded SHA-256
  selftests/bpf: Add stress test for rqspinlock in NMI
  selftests/bpf: Add test case for different expected_attach_type
  bpf: Enforce expected_attach_type for tailcall compatibility
  bpftool: Remove duplicate string.h header
  bpf: Remove duplicate crypto/sha2.h header
  libbpf: Fix error when st-prefix_ops and ops from differ btf
  selftests/bpf: Test changing packet data from kfunc
  selftests/bpf: Add stacktrace map lookup_and_delete_elem test case
  selftests/bpf: Refactor stacktrace_map case with skeleton
  bpf: Add lookup_and_delete_elem for BPF_MAP_STACK_TRACE
  selftests/bpf: Fix flaky bpf_cookie selftest
  selftests/bpf: Test changing packet data from global functions with a kfunc
  bpf: Emit struct bpf_xdp_sock type in vmlinux BTF
  selftests/bpf: Task_work selftest cleanup fixes
  MAINTAINERS: Delete inactive maintainers from AF_XDP
  bpf: Mark kfuncs as __noclone
  selftests/bpf: Add kprobe multi write ctx attach test
  selftests/bpf: Add kprobe write ctx attach test
  selftests/bpf: Add uprobe context ip register change test
  ...

Instead of sharing sd->defer_list & sd->defer_count with
many cpus, add one pair for each NUMA node.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250928084934.3266948-4-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The active-backup bonding mode supports XFRM ESP offload. However, when
a bond is added using command like `ip link add bond0 type bond mode 1
miimon 100`, the `ethtool -k` command shows that the XFRM ESP offload is
disabled. This occurs because, in bond_newlink(), we change bond link
first and register bond device later. So the XFRM feature update in
bond_option_mode_set() is not called as the bond device is not yet
registered, leading to the offload feature not being set successfully.

To resolve this issue, we can modify the code order in bond_newlink() to
ensure that the bond device is registered first before changing the bond
link parameters. This change will allow the XFRM ESP offload feature to be
correctly enabled.

Fixes: 007ab5345545 ("bonding: fix feature flag setting at init time")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://patch.msgid.link/20250925023304.472186-1-liuhangbin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

This reverts commit 4effb335b5dab08cb6e2c38d038910f8b527cfc9.

This was a benefit for UDP flood case, which was later greatly improved
with commits 6471658dc66c ("udp: use skb_attempt_defer_free()")
and b650bf0977d3 ("udp: remove busylock and add per NUMA queues").

Apparently blamed commit added a regression for RAW sockets, possibly
because they do not use the dual RX queue strategy that UDP has.

sock_queue_rcv_skb_reason() and RAW recvmsg() compete for sk_receive_buf
and sk_rmem_alloc changes, and them being in the same
cache line reduce performance.

Fixes: 4effb335b5da ("net: group sk_backlog and sk_receive_queue")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202509281326.f605b4eb-lkp@intel.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: David Ahern <dsahern@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250929182112.824154-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

To leverage the auto-tuning improvements brought by commit 2da35e4b4df9
("Merge branch 'tcp-receive-side-improvements'"), the MPTCP stack need
to access the mentioned helper.

Acked-by: Geliang Tang <geliang@kernel.org>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-2-5da266aa9c1a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull namespace updates from Christian Brauner:
 "This contains a larger set of changes around the generic namespace
  infrastructure of the kernel.

  Each specific namespace type (net, cgroup, mnt, ...) embedds a struct
  ns_common which carries the reference count of the namespace and so
  on.

  We open-coded and cargo-culted so many quirks for each namespace type
  that it just wasn't scalable anymore. So given there's a bunch of new
  changes coming in that area I've started cleaning all of this up.

  The core change is to make it possible to correctly initialize every
  namespace uniformly and derive the correct initialization settings
  from the type of the namespace such as namespace operations, namespace
  type and so on. This leaves the new ns_common_init() function with a
  single parameter which is the specific namespace type which derives
  the correct parameters statically. This also means the compiler will
  yell as soon as someone does something remotely fishy.

  The ns_common_init() addition also allows us to remove ns_alloc_inum()
  and drops any special-casing of the initial network namespace in the
  network namespace initialization code that Linus complained about.

  Another part is reworking the reference counting. The reference
  counting was open-coded and copy-pasted for each namespace type even
  though they all followed the same rules. This also removes all open
  accesses to the reference count and makes it private and only uses a
  very small set of dedicated helpers to manipulate them just like we do
  for e.g., files.

  In addition this generalizes the mount namespace iteration
  infrastructure introduced a few cycles ago. As reminder, the vfs makes
  it possible to iterate sequentially and bidirectionally through all
  mount namespaces on the system or all mount namespaces that the caller
  holds privilege over. This allow userspace to iterate over all mounts
  in all mount namespaces using the listmount() and statmount() system
  call.

  Each mount namespace has a unique identifier for the lifetime of the
  systems that is exposed to userspace. The network namespace also has a
  unique identifier working exactly the same way. This extends the
  concept to all other namespace types.

  The new nstree type makes it possible to lookup namespaces purely by
  their identifier and to walk the namespace list sequentially and
  bidirectionally for all namespace types, allowing userspace to iterate
  through all namespaces. Looking up namespaces in the namespace tree
  works completely locklessly.

  This also means we can move the mount namespace onto the generic
  infrastructure and remove a bunch of code and members from struct
  mnt_namespace itself.

  There's a bunch of stuff coming on top of this in the future but for
  now this uses the generic namespace tree to extend a concept
  introduced first for pidfs a few cycles ago. For a while now we have
  supported pidfs file handles for pidfds. This has proven to be very
  useful.

  This extends the concept to cover namespaces as well. It is possible
  to encode and decode namespace file handles using the common
  name_to_handle_at() and open_by_handle_at() apis.

  As with pidfs file handles, namespace file handles are exhaustive,
  meaning it is not required to actually hold a reference to nsfs in
  able to decode aka open_by_handle_at() a namespace file handle.
  Instead the FD_NSFS_ROOT constant can be passed which will let the
  kernel grab a reference to the root of nsfs internally and thus decode
  the file handle.

  Namespaces file descriptors can already be derived from pidfds which
  means they aren't subject to overmount protection bugs. IOW, it's
  irrelevant if the caller would not have access to an appropriate
  /proc/<pid>/ns/ directory as they could always just derive the
  namespace based on a pidfd already.

  It has the same advantage as pidfds. It's possible to reliably and for
  the lifetime of the system refer to a namespace without pinning any
  resources and to compare them trivially.

  Permission checking is kept simple. If the caller is located in the
  namespace the file handle refers to they are able to open it otherwise
  they must hold privilege over the owning namespace of the relevant
  namespace.

  The namespace file handle layout is exposed as uapi and has a stable
  and extensible format. For now it simply contains the namespace
  identifier, the namespace type, and the inode number. The stable
  format means that userspace may construct its own namespace file
  handles without going through name_to_handle_at() as they are already
  allowed for pidfs and cgroup file handles"

* tag 'namespace-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (65 commits)
  ns: drop assert
  ns: move ns type into struct ns_common
  nstree: make struct ns_tree private
  ns: add ns_debug()
  ns: simplify ns_common_init() further
  cgroup: add missing ns_common include
  ns: use inode initializer for initial namespaces
  selftests/namespaces: verify initial namespace inode numbers
  ns: rename to __ns_ref
  nsfs: port to ns_ref_*() helpers
  net: port to ns_ref_*() helpers
  uts: port to ns_ref_*() helpers
  ipv4: use check_net()
  net: use check_net()
  net-sysfs: use check_net()
  user: port to ns_ref_*() helpers
  time: port to ns_ref_*() helpers
  pid: port to ns_ref_*() helpers
  ipc: port to ns_ref_*() helpers
  cgroup: port to ns_ref_*() helpers
  ...