Tunnel xmit functions (iptunnel_xmit, ip6tunnel_xmit) lack their own
recursion limit. When a bond device in broadcast mode has GRE tap
interfaces as slaves, and those GRE tunnels route back through the
bond, multicast/broadcast traffic triggers infinite recursion between
bond_xmit_broadcast() and ip_tunnel_xmit()/ip6_tnl_xmit(), causing
kernel stack overflow.

The existing XMIT_RECURSION_LIMIT (8) in the no-qdisc path is not
sufficient because tunnel recursion involves route lookups and full IP
output, consuming much more stack per level. Use a lower limit of 4
(IP_TUNNEL_RECURSION_LIMIT) to prevent overflow.

Add recursion detection using dev_xmit_recursion helpers directly in
iptunnel_xmit() and ip6tunnel_xmit() to cover all IPv4/IPv6 tunnel
paths including UDP encapsulated tunnels (VXLAN, Geneve, etc.).

Move dev_xmit_recursion helpers from net/core/dev.h to public header
include/linux/netdevice.h so they can be used by tunnel code.

 BUG: KASAN: stack-out-of-bounds in blake2s.constprop.0+0xe7/0x160
 Write of size 32 at addr ffff88810033fed0 by task kworker/0:1/11
 Workqueue: mld mld_ifc_work
 Call Trace:
  <TASK>
  __build_flow_key.constprop.0 (net/ipv4/route.c:515)
  ip_rt_update_pmtu (net/ipv4/route.c:1073)
  iptunnel_xmit (net/ipv4/ip_tunnel_core.c:84)
  ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)
  gre_tap_xmit (net/ipv4/ip_gre.c:779)
  dev_hard_start_xmit (net/core/dev.c:3887)
  sch_direct_xmit (net/sched/sch_generic.c:347)
  __dev_queue_xmit (net/core/dev.c:4802)
  bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)
  bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)
  bond_start_xmit (drivers/net/bonding/bond_main.c:5530)
  dev_hard_start_xmit (net/core/dev.c:3887)
  __dev_queue_xmit (net/core/dev.c:4841)
  ip_finish_output2 (net/ipv4/ip_output.c:237)
  ip_output (net/ipv4/ip_output.c:438)
  iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)
  gre_tap_xmit (net/ipv4/ip_gre.c:779)
  dev_hard_start_xmit (net/core/dev.c:3887)
  sch_direct_xmit (net/sched/sch_generic.c:347)
  __dev_queue_xmit (net/core/dev.c:4802)
  bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)
  bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)
  bond_start_xmit (drivers/net/bonding/bond_main.c:5530)
  dev_hard_start_xmit (net/core/dev.c:3887)
  __dev_queue_xmit (net/core/dev.c:4841)
  ip_finish_output2 (net/ipv4/ip_output.c:237)
  ip_output (net/ipv4/ip_output.c:438)
  iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)
  ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)
  gre_tap_xmit (net/ipv4/ip_gre.c:779)
  dev_hard_start_xmit (net/core/dev.c:3887)
  sch_direct_xmit (net/sched/sch_generic.c:347)
  __dev_queue_xmit (net/core/dev.c:4802)
  bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)
  bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)
  bond_start_xmit (drivers/net/bonding/bond_main.c:5530)
  dev_hard_start_xmit (net/core/dev.c:3887)
  __dev_queue_xmit (net/core/dev.c:4841)
  mld_sendpack
  mld_ifc_work
  process_one_work
  worker_thread
  </TASK>

Fixes: 745e20f1b626 ("net: add a recursion limit in xmit path")
Reported-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Link: https://patch.msgid.link/20260306160133.3852900-2-bestswngs@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

I imagine (tm) that as the number of per-queue configuration
options grows some of them may conflict for certain drivers.
While the drivers can obviously do all the validation locally
doing so is fairly inconvenient as the config is fed to drivers
piecemeal via different ops (for different params and NIC-wide
vs per-queue).

Add a centralized callback for validating the queue config
in queue ops. The callback gets invoked before memory provider
is installed, and in the future should also be called when ring
params are modified.

The validation is done after each layer of configuration.
Since we can't fail MP un-binding we must make sure that
the config is valid both before and after MP overrides are
applied. This is moot for now since the set of MP and device
configs are disjoint. It will matter significantly in the future,
so adding it now so that we don't forget..

Link: https://patch.msgid.link/20260122005113.2476634-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This reverts commit 77b9c4a438fc66e2ab004c411056b3fb71a54f2c, reversing
changes made to 4515ec4ad58a37e70a9e1256c0b993958c9b7497:

 931420a2fc36 ("selftests/net: Add netkit container tests")
 ab771c938d9a ("selftests/net: Make NetDrvContEnv support queue leasing")
 6be87fbb2776 ("selftests/net: Add env for container based tests")
 61d99ce3dfc2 ("selftests/net: Add bpf skb forwarding program")
 920da3634194 ("netkit: Add xsk support for af_xdp applications")
 eef51113f8af ("netkit: Add netkit notifier to check for unregistering devices")
 b5ef109d22d4 ("netkit: Implement rtnl_link_ops->alloc and ndo_queue_create")
 b5c3fa4a0b16 ("netkit: Add single device mode for netkit")
 0073d2fd679d ("xsk: Proxy pool management for leased queues")
 1ecea95dd3b5 ("xsk: Extend xsk_rcv_check validation")
 804bf334d08a ("net: Proxy netdev_queue_get_dma_dev for leased queues")
 0caa9a8ddec3 ("net: Proxy net_mp_{open,close}_rxq for leased queues")
 ff8889ff9107 ("net, ethtool: Disallow leased real rxqs to be resized")
 9e2103f36110 ("net: Add lease info to queue-get response")
 31127deddef4 ("net: Implement netdev_nl_queue_create_doit")
 a5546e18f77c ("net: Add queue-create operation")

The series will conflict with io_uring work, and the code needs more
polish.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Implement netdev_nl_queue_create_doit which creates a new rx queue in a
virtual netdev and then leases it to a rx queue in a physical netdev.

Example with ynl client:

  # ./pyynl/cli.py \
      --spec ~/netlink/specs/netdev.yaml \
      --do queue-create \
      --json '{"ifindex": 8, "type": "rx", "lease": {"ifindex": 4, "queue": {"type": "rx", "id": 15}}}'
  {'id': 1}

Note that the netdevice locking order is always from the virtual to
the physical device.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260115082603.219152-3-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Pull io_uring updates from Jens Axboe:

 - Unify how task_work cancelations are detected, placing it in the
   task_work running state rather than needing to check the task state

 - Series cleaning up and moving the cancelation code to where it
   belongs, in cancel.c

 - Cleanup of waitid and futex argument handling

 - Add support for mixed sized SQEs. 6.18 added support for mixed sized
   CQEs, improving flexibility and efficiency of workloads that need big
   CQEs. This adds similar support for SQEs, where the occasional need
   for a 128b SQE doesn't necessitate having all SQEs be 128b in size

 - Introduce zcrx and SQ/CQ layout queries. The former returns what zcrx
   features are available. And both return the ring size information to
   help with allocation size calculation for user provided rings like
   IORING_SETUP_NO_MMAP and IORING_MEM_REGION_TYPE_USER

 - Zcrx updates for 6.19. It includes a bunch of small patches,
   IORING_REGISTER_ZCRX_CTRL and RQ flushing and David's work on sharing
   zcrx b/w multiple io_uring instances

 - Series cleaning up ring initializations, notable deduplicating ring
   size and offset calculations. It also moves most of the checking
   before doing any allocations, making the code simpler

 - Add support for getsockname and getpeername, which is mostly a
   trivial hookup after a bit of refactoring on the networking side

 - Various fixes and cleanups

* tag 'for-6.19/io_uring-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (68 commits)
  io_uring: Introduce getsockname io_uring cmd
  socket: Split out a getsockname helper for io_uring
  socket: Unify getsockname and getpeername implementation
  io_uring/query: drop unused io_handle_query_entry() ctx arg
  io_uring/kbuf: remove obsolete buf_nr_pages and update comments
  io_uring/register: use correct location for io_rings_layout
  io_uring/zcrx: share an ifq between rings
  io_uring/zcrx: add io_fill_zcrx_offsets()
  io_uring/zcrx: export zcrx via a file
  io_uring/zcrx: move io_zcrx_scrub() and dependencies up
  io_uring/zcrx: count zcrx users
  io_uring/zcrx: add sync refill queue flushing
  io_uring/zcrx: introduce IORING_REGISTER_ZCRX_CTRL
  io_uring/zcrx: elide passing msg flags
  io_uring/zcrx: use folio_nr_pages() instead of shift operation
  io_uring/zcrx: convert to use netmem_desc
  io_uring/query: introduce rings info query
  io_uring/query: introduce zcrx query
  io_uring: move cq/sq user offset init around
  io_uring: pre-calculate scq layout
  ...

Need to call netdev_get_by_index_lock() from io_uring/zcrx.c, but it is
currently private to net. Export the function in linux/netdevice.h.

Signed-off-by: David Wei <dw@davidwei.uk>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add a new state NAPI_STATE_THREADED_BUSY_POLL to the NAPI state enum to
enable and disable threaded busy polling.

When threaded busy polling is enabled for a NAPI, enable
NAPI_STATE_THREADED also.

When the threaded NAPI is scheduled, set NAPI_STATE_IN_BUSY_POLL to
signal napi_complete_done not to rearm interrupts.

Whenever NAPI_STATE_THREADED_BUSY_POLL is unset, the
NAPI_STATE_IN_BUSY_POLL will be unset, napi_complete_done unsets the
NAPI_STATE_SCHED_THREADED bit also, which in turn will make the kthread
go to sleep.

Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Martin Karsten <mkarsten@uwaterloo.ca>
Tested-by: Martin Karsten <mkarsten@uwaterloo.ca>
Link: https://patch.msgid.link/20251028203007.575686-2-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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 following order of calls currently deadlocks if:
 - device has threaded=1; and
 - NAPI has persistent config with threaded=0.

  netif_napi_add_weight_config()
    dev->threaded == 1
      napi_kthread_create()

  napi_enable()
    napi_restore_config()
      napi_set_threaded(0)
        napi_stop_kthread()
	  while (NAPIF_STATE_SCHED)
	    msleep(20)

We deadlock because disabled NAPI has STATE_SCHED set.
Creating a thread in netif_napi_add() just to destroy it in
napi_disable() is fairly ugly in the first place. Let's read
both the device config and the NAPI config in netif_napi_add().

Fixes: e6d76268813d ("net: Update threaded state in napi config in netif_set_threaded")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Joe Damato <joe@dama.to>
Link: https://patch.msgid.link/20250809001205.1147153-4-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Instead of using '0' and '1' for napi threaded state use an enum with
'disabled' and 'enabled' states.

Tested:
 ./tools/testing/selftests/net/nl_netdev.py
 TAP version 13
 1..7
 ok 1 nl_netdev.empty_check
 ok 2 nl_netdev.lo_check
 ok 3 nl_netdev.page_pool_check
 ok 4 nl_netdev.napi_list_check
 ok 5 nl_netdev.dev_set_threaded
 ok 6 nl_netdev.napi_set_threaded
 ok 7 nl_netdev.nsim_rxq_reset_down
 # Totals: pass:7 fail:0 xfail:0 xpass:0 skip:0 error:0

Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Link: https://patch.msgid.link/20250723013031.2911384-4-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>