[ Upstream commit 983512f3a87fd8dc4c94dfa6b596b6e57df5aad7 ]

skb_may_tx_timestamp() may acquire sock::sk_callback_lock. The lock must
not be taken in IRQ context, only softirq is okay. A few drivers receive
the timestamp via a dedicated interrupt and complete the TX timestamp
from that handler. This will lead to a deadlock if the lock is already
write-locked on the same CPU.

Taking the lock can be avoided. The socket (pointed by the skb) will
remain valid until the skb is released. The ->sk_socket and ->file
member will be set to NULL once the user closes the socket which may
happen before the timestamp arrives.
If we happen to observe the pointer while the socket is closing but
before the pointer is set to NULL then we may use it because both
pointer (and the file's cred member) are RCU freed.

Drop the lock. Use READ_ONCE() to obtain the individual pointer. Add a
matching WRITE_ONCE() where the pointer are cleared.

Link: https://lore.kernel.org/all/20260205145104.iWinkXHv@linutronix.de
Fixes: b245be1f4db1a ("net-timestamp: no-payload only sysctl")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260220183858.N4ERjFW6@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@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
  ...

Convert the get_user() and __put_user() code to the
fast masked_user_access_begin()/unsafe_{get|put}_user()
variant.

This patch increases the performance of an UDP recvfrom()
receiver (netserver) on 120 bytes messages by 7 %
on an AMD EPYC 7B12 64-Core Processor platform.

Presence of audit_sockaddr() makes difficult
to avoid the stac/clac pair in the copy_to_user() call,
this is left for a future patch.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250925230929.3727873-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

For a user mode library to avoid generating SIGPIPE signals (e.g.
because this behaviour is not portable across operating systems) is
cumbersome. It is generally bad form to change the process-wide signal
mask in a library, so a local solution is needed instead.

For I/O performed directly using system calls (synchronous or readiness
based asynchronous) this currently involves applying a thread-specific
signal mask before the operation and reverting it afterwards. This can be
avoided when it is known that the file descriptor refers to neither a
pipe nor a socket, but a conservative implementation must always apply
the mask. This incurs the cost of two additional system calls. In the
case of sockets, the existing MSG_NOSIGNAL flag can be used with send.

For asynchronous I/O performed using io_uring, currently the only option
(apart from MSG_NOSIGNAL for sockets), is to mask SIGPIPE entirely in the
call to io_uring_enter. Thankfully io_uring_enter takes a signal mask, so
only a single syscall is needed. However, copying the signal mask on
every call incurs a non-zero performance penalty. Furthermore, this mask
applies to all completions, meaning that if the non-signaling behaviour
is desired only for some subset of operations, the desired signals must
be raised manually from user-mode depending on the completed operation.

Add RWF_NOSIGNAL flag for pwritev2. This flag prevents the SIGPIPE signal
from being raised when writing on disconnected pipes or sockets. The flag
is handled directly by the pipe filesystem and converted to the existing
MSG_NOSIGNAL flag for sockets.

Signed-off-by: Lauri Vasama <git@vasama.org>
Link: https://lore.kernel.org/20250827133901.1820771-1-git@vasama.org
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>

sk->sk_uid can be read while another thread changes its
value in sockfs_setattr().

Add sk_uid(const struct sock *sk) helper to factorize the needed
READ_ONCE() annotations, and add corresponding WRITE_ONCE()
where needed.

Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://patch.msgid.link/20250620133001.4090592-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add a helper function skb_get_tx_timestamp() that returns a tx timestamp
associated with an error queue skb.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/702357dd8936ef4c0d3864441e853bfe3224a677.1750065793.git.asml.silence@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Merge in late fixes to prepare for the 6.15 net-next PR.

No conflicts, adjacent changes:

drivers/net/ethernet/broadcom/bnxt/bnxt.c
  919f9f497dbc ("eth: bnxt: fix out-of-range access of vnic_info array")
  fe96d717d38e ("bnxt_en: Extend queue stop/start for TX rings")

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

Add SOF_TIMESTAMPING_TX_COMPLETION, for requesting a software timestamp
when hardware reports a packet completed.

Completion tstamp is useful for Bluetooth, as hardware timestamps do not
exist in the HCI specification except for ISO packets, and the hardware
has a queue where packets may wait.  In this case the software SND
timestamp only reflects the kernel-side part of the total latency
(usually small) and queue length (usually 0 unless HW buffers
congested), whereas the completion report time is more informative of
the true latency.

It may also be useful in other cases where HW TX timestamps cannot be
obtained and user wants to estimate an upper bound to when the TX
probably happened.

Signed-off-by: Pauli Virtanen <pav@iki.fi>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

SIOCBRDELIF is passed to dev_ioctl() first and later forwarded to
br_ioctl_call(), which causes unnecessary RTNL dance and the splat
below [0] under RTNL pressure.

Let's say Thread A is trying to detach a device from a bridge and
Thread B is trying to remove the bridge.

In dev_ioctl(), Thread A bumps the bridge device's refcnt by
netdev_hold() and releases RTNL because the following br_ioctl_call()
also re-acquires RTNL.

In the race window, Thread B could acquire RTNL and try to remove
the bridge device.  Then, rtnl_unlock() by Thread B will release RTNL
and wait for netdev_put() by Thread A.

Thread A, however, must hold RTNL after the unlock in dev_ifsioc(),
which may take long under RTNL pressure, resulting in the splat by
Thread B.

  Thread A (SIOCBRDELIF)           Thread B (SIOCBRDELBR)
  ----------------------           ----------------------
  sock_ioctl                       sock_ioctl
  `- sock_do_ioctl                 `- br_ioctl_call
     `- dev_ioctl                     `- br_ioctl_stub
        |- rtnl_lock                     |
        |- dev_ifsioc                    '
        '  |- dev = __dev_get_by_name(...)
           |- netdev_hold(dev, ...)      .
       /   |- rtnl_unlock  ------.       |
       |   |- br_ioctl_call       `--->  |- rtnl_lock
  Race |   |  `- br_ioctl_stub           |- br_del_bridge
  Window   |     |                       |  |- dev = __dev_get_by_name(...)
       |   |     |  May take long        |  `- br_dev_delete(dev, ...)
       |   |     |  under RTNL pressure  |     `- unregister_netdevice_queue(dev, ...)
       |   |     |               |       `- rtnl_unlock
       \   |     |- rtnl_lock  <-'          `- netdev_run_todo
           |     |- ...                        `- netdev_run_todo
           |     `- rtnl_unlock                   |- __rtnl_unlock
           |                                      |- netdev_wait_allrefs_any
           |- netdev_put(dev, ...)  <----------------'
                                                Wait refcnt decrement
                                                and log splat below

To avoid blocking SIOCBRDELBR unnecessarily, let's not call
dev_ioctl() for SIOCBRADDIF and SIOCBRDELIF.

In the dev_ioctl() path, we do the following:

  1. Copy struct ifreq by get_user_ifreq in sock_do_ioctl()
  2. Check CAP_NET_ADMIN in dev_ioctl()
  3. Call dev_load() in dev_ioctl()
  4. Fetch the master dev from ifr.ifr_name in dev_ifsioc()

3. can be done by request_module() in br_ioctl_call(), so we move
1., 2., and 4. to br_ioctl_stub().

Note that 2. is also checked later in add_del_if(), but it's better
performed before RTNL.

SIOCBRADDIF and SIOCBRDELIF have been processed in dev_ioctl() since
the pre-git era, and there seems to be no specific reason to process
them there.

[0]:
unregister_netdevice: waiting for wpan3 to become free. Usage count = 2
ref_tracker: wpan3@ffff8880662d8608 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4282 [inline]
     netdev_hold include/linux/netdevice.h:4311 [inline]
     dev_ifsioc+0xc6a/0x1160 net/core/dev_ioctl.c:624
     dev_ioctl+0x255/0x10c0 net/core/dev_ioctl.c:826
     sock_do_ioctl+0x1ca/0x260 net/socket.c:1213
     sock_ioctl+0x23a/0x6c0 net/socket.c:1318
     vfs_ioctl fs/ioctl.c:51 [inline]
     __do_sys_ioctl fs/ioctl.c:906 [inline]
     __se_sys_ioctl fs/ioctl.c:892 [inline]
     __x64_sys_ioctl+0x1a4/0x210 fs/ioctl.c:892
     do_syscall_x64 arch/x86/entry/common.c:52 [inline]
     do_syscall_64+0xcb/0x250 arch/x86/entry/common.c:83
     entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fixes: 893b19587534 ("net: bridge: fix ioctl locking")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Reported-by: yan kang <kangyan91@outlook.com>
Reported-by: yue sun <samsun1006219@gmail.com>
Closes: https://lore.kernel.org/netdev/SY8P300MB0421225D54EB92762AE8F0F2A1D32@SY8P300MB0421.AUSP300.PROD.OUTLOOK.COM/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20250316192851.19781-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The linked series wants to add skb tx completion timestamps.
That needs a bit in skb_shared_info.tx_flags, but all are in use.

A per-skb bit is only needed for features that are configured on a
per packet basis. Per socket features can be read from sk->sk_tsflags.

Per packet tsflags can be set in sendmsg using cmsg, but only those in
SOF_TIMESTAMPING_TX_RECORD_MASK.

Per packet tsflags can also be set without cmsg by sandwiching a
send inbetween two setsockopts:

    val |= SOF_TIMESTAMPING_$FEATURE;
    setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, &val, sizeof(val));
    write(fd, buf, sz);
    val &= ~SOF_TIMESTAMPING_$FEATURE;
    setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, &val, sizeof(val));

Changing a datapath test from skb_shinfo(skb)->tx_flags to
skb->sk->sk_tsflags can change behavior in that case, as the tx_flags
is written before the second setsockopt updates sk_tsflags.

Therefore, only bits can be reclaimed that cannot be set by cmsg and
are also highly unlikely to be used to target individual packets
otherwise.

Free up the bit currently used for SKBTX_HW_TSTAMP_USE_CYCLES. This
selects between clock and free running counter source for HW TX
timestamps. It is probable that all packets of the same socket will
always use the same source.

Link: https://lore.kernel.org/netdev/cover.1739988644.git.pav@iki.fi/
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Link: https://patch.msgid.link/20250225023416.2088705-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>