This is strictly related to commit fb7a0d33 ("mptcp: ensure snd_nxt
is properly initialized on connect"). It turns out that syzkaller can
trigger the retransmit after fallback and before processing any other
incoming packet - so that snd_una is still left uninitialized.

Address the issue explicitly initializing snd_una together with snd_nxt
and write_seq.
Suggested-by: Mat Martineau <martineau@kernel.org>
Fixes: 8fd73804 ("mptcp: fallback in case of simultaneous connect")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/485Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240607-upstream-net-20240607-misc-fixes-v1-1-1ab9ddfa3d00@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

When the noop_qdisc owner isn't initialized, then it will be 0,
so packets will erroneously be regarded as having been subject
to recursion as long as only CPU 0 queues them. For non-SMP,
that's all packets, of course. This causes a change in what's
reported to userspace, normally noop_qdisc would drop packets
silently, but with this change the syscall returns -ENOBUFS if
RECVERR is also set on the socket.

Fix this by initializing the owner field to -1, just like it
would be for dynamically allocated qdiscs by qdisc_alloc().

Fixes: 0f022d32 ("net/sched: Fix mirred deadlock on device recursion")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240607175340.786bfb938803.I493bf8422e36be4454c08880a8d3703cea8e421a@changeidSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Tariq Toukan says:

====================
geneve fixes

This small patchset by Gal provides bug fixes to the geneve tunnels flows.

Patch 1 fixes an incorrect value returned by the inner network header
offset helper.
Patch 2 fixes an issue inside the mlx5e tunneling flow. It 'happened' to
be harmless so far, before applying patch 1.

Series generated against:
commit d30d0e49 ("Merge tag 'net-6.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net")
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Move the vxlan_features_check() call to after we verified the packet is
a tunneled VXLAN packet.

Without this, tunneled UDP non-VXLAN packets (for ex. GENENVE) might
wrongly not get offloaded.
In some cases, it worked by chance as GENEVE header is the same size as
VXLAN, but it is obviously incorrect.

Fixes: e3cfc7e6 ("net/mlx5e: TX, Add geneve tunnel stateless offload support")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When innerprotoinherit is set, the tunneled packets do not have an inner
Ethernet header.
Change 'maclen' to not always assume the header length is ETH_HLEN, as
there might not be a MAC header.

This resolves issues with drivers (e.g. mlx5, in
mlx5e_tx_tunnel_accel()) who rely on the skb inner network header offset
to be correct, and use it for TX offloads.

Fixes: d8a6213d ("geneve: fix header validation in geneve[6]_xmit_skb")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The documentation for device_get_named_child_node() mentions this
important point:

"
The caller is responsible for calling fwnode_handle_put() on the
returned fwnode pointer.
"

Add fwnode_handle_put() to avoid leaked references.

Fixes: 1e264f9d ("net: dsa: qca8k: add LEDs basic support")
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tcp_v6_syn_recv_sock() calls ip6_dst_store() before
inet_sk(newsk)->pinet6 has been set up.

This means ip6_dst_store() writes over the parent (listener)
np->dst_cookie.

This is racy because multiple threads could share the same
parent and their final np->dst_cookie could be wrong.

Move ip6_dst_store() call after inet_sk(newsk)->pinet6
has been changed and after the copy of parent ipv6_pinfo.

Fixes: e994b2f0 ("tcp: do not lock listener to process SYN packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The default ndo_get_iflink() implementation returns the current ifindex
of the netdev. But the overridden nsim_get_iflink() returns 0 if the
current nsim is not linked, breaking backwards compatibility for
userspace that depend on this behaviour.

Fix the problem by returning the current ifindex if not linked to a
peer.

Fixes: 8debcf58 ("netdevsim: add ndo_get_iflink() implementation")
Reported-by: Yu Watanabe <watanabe.yu@gmail.com>
Suggested-by: Yu Watanabe <watanabe.yu@gmail.com>
Signed-off-by: David Wei <dw@davidwei.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 070246e4 ("net: stmmac: Fix for mismatched host/device DMA
address width") added support in the stmmac driver for platform drivers
to indicate the host DMA width, but left it up to authors of the
specific platforms to indicate if their width differed from the addr64
register read from the MAC itself.

Qualcomm's EMAC4 integration supports only up to 36 bit width (as
opposed to the addr64 register indicating 40 bit width). Let's indicate
that in the platform driver to avoid a scenario where the driver will
allocate descriptors of size that is supported by the CPU which in our
case is 36 bit, but as the addr64 register is still capable of 40 bits
the device will use two descriptors as one address.

Fixes: 8c4d92e8 ("net: stmmac: dwmac-qcom-ethqos: add support for emac4 on sa8775p platforms")
Signed-off-by: Sagar Cheluvegowda <quic_scheluve@quicinc.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In lio_vf_rep_copy_packet() pg_info->page is compared to a NULL value,
but then it is unconditionally passed to skb_add_rx_frag() which looks
strange and could lead to null pointer dereference.

lio_vf_rep_copy_packet() call trace looks like:
	octeon_droq_process_packets
	 octeon_droq_fast_process_packets
	  octeon_droq_dispatch_pkt
	   octeon_create_recv_info
	    ...search in the dispatch_list...
	     ->disp_fn(rdisp->rinfo, ...)
	      lio_vf_rep_pkt_recv(struct octeon_recv_info *recv_info, ...)
In this path there is no code which sets pg_info->page to NULL.
So this check looks unneeded and doesn't solve potential problem.
But I guess the author had reason to add a check and I have no such card
and can't do real test.
In addition, the code in the function liquidio_push_packet() in
liquidio/lio_core.c does exactly the same.

Based on this, I consider the most acceptable compromise solution to
adjust this issue by moving skb_add_rx_frag() into conditional scope.

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

Fixes: 1f233f32 ("liquidio: switchdev support for LiquidIO NIC")
Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jijie Shao says:

====================
There are some bugfix for the HNS3 ethernet driver

There are some bugfix for the HNS3 ethernet driver
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently hns3 ring buffer init process would hold cpu too long with big
Tx/Rx ring depth. This could cause soft lockup.

So this patch adds cond_resched() to the process. Then cpu can break to
run other tasks instead of busy looping.

Fixes: a723fb8e ("net: hns3: refine for set ring parameters")
Signed-off-by: Jie Wang <wangjie125@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

When link status change, the nic driver need to notify the roce
driver to handle this event, but at this time, the roce driver
may uninit, then cause kernel crash.

To fix the problem, when link status change, need to check
whether the roce registered, and when uninit, need to wait link
update finish.

Fixes: 45e92b7e ("net: hns3: add calling roce callback function when link status change")
Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Modify license to include dual licensing as GPL-2.0-only OR MIT
license for TI specific phy header files. This allows for Linux
kernel files to be used in other Operating System ecosystems
such as Zephyr or FreeBSD.

While at this, update the GPL-2.0 to be GPL-2.0-only to be in sync
with latest SPDX conventions (GPL-2.0 is deprecated).

While at this, update the TI copyright year to sync with current year
to indicate license change.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Trent Piepho <tpiepho@impinj.com>
Cc: Wadim Egorov <w.egorov@phytec.de>
Cc: Kip Broadhurst <kbroadhurst@ti.com>
Signed-off-by: Udit Kumar <u-kumar1@ti.com>
Acked-by: Wadim Egorov <w.egorov@phytec.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

If the module is in SFP_MOD_ERROR, `sfp_sm_mod_remove()` will
not be run. As a consequence, `sfp_hwmon_remove()` is not getting
run either, leaving a stale `hwmon` device behind. `sfp_sm_mod_remove()`
itself checks `sfp->sm_mod_state` anyways, so this check was not
really needed in the first place.

Fixes: d2e816c0 ("net: sfp: handle module remove outside state machine")
Signed-off-by: "Csókás, Bence" <csokas.bence@prolan.hu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240605084251.63502-1-csokas.bence@prolan.huSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Pull networking fixes from Jakub Kicinski:
 "Including fixes from BPF and big collection of fixes for WiFi core and
  drivers.

  Current release - regressions:

   - vxlan: fix regression when dropping packets due to invalid src
     addresses

   - bpf: fix a potential use-after-free in bpf_link_free()

   - xdp: revert support for redirect to any xsk socket bound to the
     same UMEM as it can result in a corruption

   - virtio_net:
      - add missing lock protection when reading return code from
        control_buf
      - fix false-positive lockdep splat in DIM
      - Revert "wifi: wilc1000: convert list management to RCU"

   - wifi: ath11k: fix error path in ath11k_pcic_ext_irq_config

  Previous releases - regressions:

   - rtnetlink: make the "split" NLM_DONE handling generic, restore the
     old behavior for two cases where we started coalescing those
     messages with normal messages, breaking sloppily-coded userspace

   - wifi:
      - cfg80211: validate HE operation element parsing
      - cfg80211: fix 6 GHz scan request building
      - mt76: mt7615: add missing chanctx ops
      - ath11k: move power type check to ASSOC stage, fix connecting to
        6 GHz AP
      - ath11k: fix WCN6750 firmware crash caused by 17 num_vdevs
      - rtlwifi: ignore IEEE80211_CONF_CHANGE_RETRY_LIMITS
      - iwlwifi: mvm: fix a crash on 7265

  Previous releases - always broken:

   - ncsi: prevent multi-threaded channel probing, a spec violation

   - vmxnet3: disable rx data ring on dma allocation failure

   - ethtool: init tsinfo stats if requested, prevent unintentionally
     reporting all-zero stats on devices which don't implement any

   - dst_cache: fix possible races in less common IPv6 features

   - tcp: auth: don't consider TCP_CLOSE to be in TCP_AO_ESTABLISHED

   - ax25: fix two refcounting bugs

   - eth: ionic: fix kernel panic in XDP_TX action

  Misc:

   - tcp: count CLOSE-WAIT sockets for TCP_MIB_CURRESTAB"

* tag 'net-6.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (107 commits)
  selftests: net: lib: set 'i' as local
  selftests: net: lib: avoid error removing empty netns name
  selftests: net: lib: support errexit with busywait
  net: ethtool: fix the error condition in ethtool_get_phy_stats_ethtool()
  ipv6: fix possible race in __fib6_drop_pcpu_from()
  af_unix: Annotate data-race of sk->sk_shutdown in sk_diag_fill().
  af_unix: Use skb_queue_len_lockless() in sk_diag_show_rqlen().
  af_unix: Use skb_queue_empty_lockless() in unix_release_sock().
  af_unix: Use unix_recvq_full_lockless() in unix_stream_connect().
  af_unix: Annotate data-race of net->unx.sysctl_max_dgram_qlen.
  af_unix: Annotate data-races around sk->sk_sndbuf.
  af_unix: Annotate data-races around sk->sk_state in UNIX_DIAG.
  af_unix: Annotate data-race of sk->sk_state in unix_stream_read_skb().
  af_unix: Annotate data-races around sk->sk_state in sendmsg() and recvmsg().
  af_unix: Annotate data-race of sk->sk_state in unix_accept().
  af_unix: Annotate data-race of sk->sk_state in unix_stream_connect().
  af_unix: Annotate data-races around sk->sk_state in unix_write_space() and poll().
  af_unix: Annotate data-race of sk->sk_state in unix_inq_len().
  af_unix: Annodate data-races around sk->sk_state for writers.
  af_unix: Set sk->sk_state under unix_state_lock() for truly disconencted peer.
  ...

Pull tomoyo fixlet from Tetsuo Handa:
 "Single patch to update project links, no behavior changes"

* tag 'tomoyo-pr-20240606' of git://git.code.sf.net/p/tomoyo/tomoyo:
  tomoyo: update project links

Pull EFI fixes from Ard Biesheuvel:

 - Ensure that .discard sections are really discarded in the EFI zboot
   image build

 - Return proper error numbers from efi-pstore

 - Add __nocfi annotations to EFI runtime wrappers

* tag 'efi-fixes-for-v6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: Add missing __nocfi annotations to runtime wrappers
  efi: pstore: Return proper errors on UEFI failures
  efi/libstub: zboot.lds: Discard .discard sections

Matthieu Baerts says:

====================
selftests: net: lib: small fixes

While looking at using 'lib.sh' for the MPTCP selftests [1], we found
some small issues with 'lib.sh'. Here they are:

- Patch 1: fix 'errexit' (set -e) support with busywait. 'errexit' is
  supported in some functions, not all. A fix for v6.8+.

- Patch 2: avoid confusing error messages linked to the cleaning part
  when the netns setup fails. A fix for v6.8+.

- Patch 3: set a variable as local to avoid accidentally changing the
  value of a another one with the same name on the caller side. A fix
  for v6.10-rc1+.

Link: https://lore.kernel.org/mptcp/5f4615c3-0621-43c5-ad25-55747a4350ce@kernel.org/T/ [1]
====================

Link: https://lore.kernel.org/r/20240605-upstream-net-20240605-selftests-net-lib-fixes-v1-0-b3afadd368c9@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Without this, the 'i' variable declared before could be overridden by
accident, e.g.

  for i in "${@}"; do
      __ksft_status_merge "${i}"  ## 'i' has been modified
      foo "${i}"                  ## using 'i' with an unexpected value
  done

After a quick look, it looks like 'i' is currently not used after having
been modified in __ksft_status_merge(), but still, better be safe than
sorry. I saw this while modifying the same file, not because I suspected
an issue somewhere.

Fixes: 596c8819 ("selftests: forwarding: Have RET track kselftest framework constants")
Acked-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240605-upstream-net-20240605-selftests-net-lib-fixes-v1-3-b3afadd368c9@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

If there is an error to create the first netns with 'setup_ns()',
'cleanup_ns()' will be called with an empty string as first parameter.

The consequences is that 'cleanup_ns()' will try to delete an invalid
netns, and wait 20 seconds if the netns list is empty.

Instead of just checking if the name is not empty, convert the string
separated by spaces to an array. Manipulating the array is cleaner, and
calling 'cleanup_ns()' with an empty array will be a no-op.

Fixes: 25ae948b ("selftests/net: add lib.sh")
Cc: stable@vger.kernel.org
Acked-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240605-upstream-net-20240605-selftests-net-lib-fixes-v1-2-b3afadd368c9@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

If errexit is enabled ('set -e'), loopy_wait -- or busywait and others
using it -- will stop after the first failure.

Note that if the returned status of loopy_wait is checked, and even if
errexit is enabled, Bash will not stop at the first error.

Fixes: 25ae948b ("selftests/net: add lib.sh")
Cc: stable@vger.kernel.org
Acked-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240605-upstream-net-20240605-selftests-net-lib-fixes-v1-1-b3afadd368c9@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Clang static checker (scan-build) warning:
net/ethtool/ioctl.c:line 2233, column 2
Called function pointer is null (null dereference).

Return '-EOPNOTSUPP' when 'ops->get_ethtool_phy_stats' is NULL to fix
this typo error.

Fixes: 201ed315 ("net/ethtool/ioctl: split ethtool_get_phy_stats into multiple helpers")
Signed-off-by: Su Hui <suhui@nfschina.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Hariprasad Kelam <hkelam@marvell.com>
Link: https://lore.kernel.org/r/20240605034742.921751-1-suhui@nfschina.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

syzbot found a race in __fib6_drop_pcpu_from() [1]

If compiler reads more than once (*ppcpu_rt),
second read could read NULL, if another cpu clears
the value in rt6_get_pcpu_route().

Add a READ_ONCE() to prevent this race.

Also add rcu_read_lock()/rcu_read_unlock() because
we rely on RCU protection while dereferencing pcpu_rt.

[1]

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]
CPU: 0 PID: 7543 Comm: kworker/u8:17 Not tainted 6.10.0-rc1-syzkaller-00013-g2bfcfd58 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: netns cleanup_net
 RIP: 0010:__fib6_drop_pcpu_from.part.0+0x10a/0x370 net/ipv6/ip6_fib.c:984
Code: f8 48 c1 e8 03 80 3c 28 00 0f 85 16 02 00 00 4d 8b 3f 4d 85 ff 74 31 e8 74 a7 fa f7 49 8d bf 90 00 00 00 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 1e 02 00 00 49 8b 87 90 00 00 00 48 8b 0c 24 48
RSP: 0018:ffffc900040df070 EFLAGS: 00010206
RAX: 0000000000000012 RBX: 0000000000000001 RCX: ffffffff89932e16
RDX: ffff888049dd1e00 RSI: ffffffff89932d7c RDI: 0000000000000091
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000001 R11: 0000000000000006 R12: ffff88807fa080b8
R13: fffffbfff1a9a07d R14: ffffed100ff41022 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32c26000 CR3: 000000005d56e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
  __fib6_drop_pcpu_from net/ipv6/ip6_fib.c:966 [inline]
  fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1027 [inline]
  fib6_purge_rt+0x7f2/0x9f0 net/ipv6/ip6_fib.c:1038
  fib6_del_route net/ipv6/ip6_fib.c:1998 [inline]
  fib6_del+0xa70/0x17b0 net/ipv6/ip6_fib.c:2043
  fib6_clean_node+0x426/0x5b0 net/ipv6/ip6_fib.c:2205
  fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2127
  fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2175
  fib6_clean_tree+0xd7/0x120 net/ipv6/ip6_fib.c:2255
  __fib6_clean_all+0x100/0x2d0 net/ipv6/ip6_fib.c:2271
  rt6_sync_down_dev net/ipv6/route.c:4906 [inline]
  rt6_disable_ip+0x7ed/0xa00 net/ipv6/route.c:4911
  addrconf_ifdown.isra.0+0x117/0x1b40 net/ipv6/addrconf.c:3855
  addrconf_notify+0x223/0x19e0 net/ipv6/addrconf.c:3778
  notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
  call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1992
  call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]
  call_netdevice_notifiers net/core/dev.c:2044 [inline]
  dev_close_many+0x333/0x6a0 net/core/dev.c:1585
  unregister_netdevice_many_notify+0x46d/0x19f0 net/core/dev.c:11193
  unregister_netdevice_many net/core/dev.c:11276 [inline]
  default_device_exit_batch+0x85b/0xae0 net/core/dev.c:11759
  ops_exit_list+0x128/0x180 net/core/net_namespace.c:178
  cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640
  process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231
  process_scheduled_works kernel/workqueue.c:3312 [inline]
  worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
  kthread+0x2c1/0x3a0 kernel/kthread.c:389
  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Fixes: d52d3997 ("ipv6: Create percpu rt6_info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20240604193549.981839-1-edumazet@google.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Kuniyuki Iwashima says:

====================
af_unix: Fix lockless access of sk->sk_state and others fields.

The patch 1 fixes a bug where SOCK_DGRAM's sk->sk_state is changed
to TCP_CLOSE even if the socket is connect()ed to another socket.

The rest of this series annotates lockless accesses to the following
fields.

  * sk->sk_state
  * sk->sk_sndbuf
  * net->unx.sysctl_max_dgram_qlen
  * sk->sk_receive_queue.qlen
  * sk->sk_shutdown

Note that with this series there is skb_queue_empty() left in
unix_dgram_disconnected() that needs to be changed to lockless
version, and unix_peer(other) access there should be protected
by unix_state_lock().

This will require some refactoring, so another series will follow.

Changes:
  v2:
    * Patch 1: Fix wrong double lock

  v1: https://lore.kernel.org/netdev/20240603143231.62085-1-kuniyu@amazon.com/
====================

Link: https://lore.kernel.org/r/20240604165241.44758-1-kuniyu@amazon.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

While dumping sockets via UNIX_DIAG, we do not hold unix_state_lock().

Let's use READ_ONCE() to read sk->sk_shutdown.

Fixes: e4e541a8 ("sock-diag: Report shutdown for inet and unix sockets (v2)")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

We can dump the socket queue length via UNIX_DIAG by specifying
UDIAG_SHOW_RQLEN.

If sk->sk_state is TCP_LISTEN, we return the recv queue length,
but here we do not hold recvq lock.

Let's use skb_queue_len_lockless() in sk_diag_show_rqlen().

Fixes: c9da99e6 ("unix_diag: Fixup RQLEN extension report")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

If the socket type is SOCK_STREAM or SOCK_SEQPACKET, unix_release_sock()
checks the length of the peer socket's recvq under unix_state_lock().

However, unix_stream_read_generic() calls skb_unlink() after releasing
the lock.  Also, for SOCK_SEQPACKET, __skb_try_recv_datagram() unlinks
skb without unix_state_lock().

Thues, unix_state_lock() does not protect qlen.

Let's use skb_queue_empty_lockless() in unix_release_sock().

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Once sk->sk_state is changed to TCP_LISTEN, it never changes.

unix_accept() takes advantage of this characteristics; it does not
hold the listener's unix_state_lock() and only acquires recvq lock
to pop one skb.

It means unix_state_lock() does not prevent the queue length from
changing in unix_stream_connect().

Thus, we need to use unix_recvq_full_lockless() to avoid data-race.

Now we remove unix_recvq_full() as no one uses it.

Note that we can remove READ_ONCE() for sk->sk_max_ack_backlog in
unix_recvq_full_lockless() because of the following reasons:

  (1) For SOCK_DGRAM, it is a written-once field in unix_create1()

  (2) For SOCK_STREAM and SOCK_SEQPACKET, it is changed under the
      listener's unix_state_lock() in unix_listen(), and we hold
      the lock in unix_stream_connect()

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net->unx.sysctl_max_dgram_qlen is exposed as a sysctl knob and can be
changed concurrently.

Let's use READ_ONCE() in unix_create1().

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

sk_setsockopt() changes sk->sk_sndbuf under lock_sock(), but it's
not used in af_unix.c.

Let's use READ_ONCE() to read sk->sk_sndbuf in unix_writable(),
unix_dgram_sendmsg(), and unix_stream_sendmsg().

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

While dumping AF_UNIX sockets via UNIX_DIAG, sk->sk_state is read
locklessly.

Let's use READ_ONCE() there.

Note that the result could be inconsistent if the socket is dumped
during the state change.  This is common for other SOCK_DIAG and
similar interfaces.

Fixes: c9da99e6 ("unix_diag: Fixup RQLEN extension report")
Fixes: 2aac7a2c ("unix_diag: Pending connections IDs NLA")
Fixes: 45a96b9b ("unix_diag: Dumping all sockets core")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

unix_stream_read_skb() is called from sk->sk_data_ready() context
where unix_state_lock() is not held.

Let's use READ_ONCE() there.

Fixes: 77462de1 ("af_unix: Add read_sock for stream socket types")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The following functions read sk->sk_state locklessly and proceed only if
the state is TCP_ESTABLISHED.

  * unix_stream_sendmsg
  * unix_stream_read_generic
  * unix_seqpacket_sendmsg
  * unix_seqpacket_recvmsg

Let's use READ_ONCE() there.

Fixes: a05d2ad1 ("af_unix: Only allow recv on connected seqpacket sockets.")
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Once sk->sk_state is changed to TCP_LISTEN, it never changes.

unix_accept() takes the advantage and reads sk->sk_state without
holding unix_state_lock().

Let's use READ_ONCE() there.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

As small optimisation, unix_stream_connect() prefetches the client's
sk->sk_state without unix_state_lock() and checks if it's TCP_CLOSE.

Later, sk->sk_state is checked again under unix_state_lock().

Let's use READ_ONCE() for the first check and TCP_CLOSE directly for
the second check.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

unix_poll() and unix_dgram_poll() read sk->sk_state locklessly and
calls unix_writable() which also reads sk->sk_state without holding
unix_state_lock().

Let's use READ_ONCE() in unix_poll() and unix_dgram_poll() and pass
it to unix_writable().

While at it, we remove TCP_SYN_SENT check in unix_dgram_poll() as
that state does not exist for AF_UNIX socket since the code was added.

Fixes: 1586a587 ("af_unix: do not report POLLOUT on listeners")
Fixes: 3c73419c ("af_unix: fix 'poll for write'/ connected DGRAM sockets")
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

ioctl(SIOCINQ) calls unix_inq_len() that checks sk->sk_state first
and returns -EINVAL if it's TCP_LISTEN.

Then, for SOCK_STREAM sockets, unix_inq_len() returns the number of
bytes in recvq.

However, unix_inq_len() does not hold unix_state_lock(), and the
concurrent listen() might change the state after checking sk->sk_state.

If the race occurs, 0 is returned for the listener, instead of -EINVAL,
because the length of skb with embryo is 0.

We could hold unix_state_lock() in unix_inq_len(), but it's overkill
given the result is true for pre-listen() TCP_CLOSE state.

So, let's use READ_ONCE() for sk->sk_state in unix_inq_len().

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

sk->sk_state is changed under unix_state_lock(), but it's read locklessly
in many places.

This patch adds WRITE_ONCE() on the writer side.

We will add READ_ONCE() to the lockless readers in the following patches.

Fixes: 83301b53 ("af_unix: Set TCP_ESTABLISHED for datagram sockets too")
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

When a SOCK_DGRAM socket connect()s to another socket, the both sockets'
sk->sk_state are changed to TCP_ESTABLISHED so that we can register them
to BPF SOCKMAP.

When the socket disconnects from the peer by connect(AF_UNSPEC), the state
is set back to TCP_CLOSE.

Then, the peer's state is also set to TCP_CLOSE, but the update is done
locklessly and unconditionally.

Let's say socket A connect()ed to B, B connect()ed to C, and A disconnects
from B.

After the first two connect()s, all three sockets' sk->sk_state are
TCP_ESTABLISHED:

  $ ss -xa
  Netid State  Recv-Q Send-Q  Local Address:Port  Peer Address:PortProcess
  u_dgr ESTAB  0      0       @A 641              * 642
  u_dgr ESTAB  0      0       @B 642              * 643
  u_dgr ESTAB  0      0       @C 643              * 0

And after the disconnect, B's state is TCP_CLOSE even though it's still
connected to C and C's state is TCP_ESTABLISHED.

  $ ss -xa
  Netid State  Recv-Q Send-Q  Local Address:Port  Peer Address:PortProcess
  u_dgr UNCONN 0      0       @A 641              * 0
  u_dgr UNCONN 0      0       @B 642              * 643
  u_dgr ESTAB  0      0       @C 643              * 0

In this case, we cannot register B to SOCKMAP.

So, when a socket disconnects from the peer, we should not set TCP_CLOSE to
the peer if the peer is connected to yet another socket, and this must be
done under unix_state_lock().

Note that we use WRITE_ONCE() for sk->sk_state as there are many lockless
readers.  These data-races will be fixed in the following patches.

Fixes: 83301b53 ("af_unix: Set TCP_ESTABLISHED for datagram sockets too")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>