Pull cgroup fixes from Tejun Heo:

 - Fix for a subtle bug in the recent release_agent permission check
   update

 - Fix for a long-standing race condition between cpuset and cpu hotplug

 - Comment updates

* 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset: Fix kernel-doc
  cgroup-v1: Correct privileges check in release_agent writes
  cgroup: clarify cgroup_css_set_fork()
  cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug

With recent fixes for the permission checking when moving a task into a cgroup
using a file descriptor to a cgroup's cgroup.procs file and calling write() it
seems a good idea to clarify CLONE_INTO_CGROUP permission checking with a
comment.

Cc: Tejun Heo <tj@kernel.org>
Cc: <cgroups@vger.kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

With write operation on psi files replacing old trigger with a new one,
the lifetime of its waitqueue is totally arbitrary. Overwriting an
existing trigger causes its waitqueue to be freed and pending poll()
will stumble on trigger->event_wait which was destroyed.
Fix this by disallowing to redefine an existing psi trigger. If a write
operation is used on a file descriptor with an already existing psi
trigger, the operation will fail with EBUSY error.
Also bypass a check for psi_disabled in the psi_trigger_destroy as the
flag can be flipped after the trigger is created, leading to a memory
leak.

Fixes: 0e94682b73bf ("psi: introduce psi monitor")
Reported-by: syzbot+cdb5dd11c97cc532efad@syzkaller.appspotmail.com
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Analyzed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220111232309.1786347-1-surenb@google.com

Pull cgroup updates from Tejun Heo:
 "Nothing too interesting. The only two noticeable changes are a subtle
  cpuset behavior fix and trace event id field being expanded to u64
  from int. Most others are code cleanups"

* 'for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset: convert 'allowed' in __cpuset_node_allowed() to be boolean
  cgroup/rstat: check updated_next only for root
  cgroup: rstat: explicitly put loop variant in while
  cgroup: return early if it is already on preloaded list
  cgroup/cpuset: Don't let child cpusets restrict parent in default hierarchy
  cgroup: Trace event cgroup id fields should be u64
  cgroup: fix a typo in comment
  cgroup: get the wrong css for css_alloc() during cgroup_init_subsys()
  cgroup: rstat: Mark benign data race to silence KCSAN

Pull networking updates from Jakub Kicinski:
 "Core
  ----

   - Defer freeing TCP skbs to the BH handler, whenever possible, or at
     least perform the freeing outside of the socket lock section to
     decrease cross-CPU allocator work and improve latency.

   - Add netdevice refcount tracking to locate sources of netdevice and
     net namespace refcount leaks.

   - Make Tx watchdog less intrusive - avoid pausing Tx and restarting
     all queues from a single CPU removing latency spikes.

   - Various small optimizations throughout the stack from Eric Dumazet.

   - Make netdev->dev_addr[] constant, force modifications to go via
     appropriate helpers to allow us to keep addresses in ordered data
     structures.

   - Replace unix_table_lock with per-hash locks, improving performance
     of bind() calls.

   - Extend skb drop tracepoint with a drop reason.

   - Allow SO_MARK and SO_PRIORITY setsockopt under CAP_NET_RAW.

  BPF
  ---

   - New helpers:
      - bpf_find_vma(), find and inspect VMAs for profiling use cases
      - bpf_loop(), runtime-bounded loop helper trading some execution
        time for much faster (if at all converging) verification
      - bpf_strncmp(), improve performance, avoid compiler flakiness
      - bpf_get_func_arg(), bpf_get_func_ret(), bpf_get_func_arg_cnt()
        for tracing programs, all inlined by the verifier

   - Support BPF relocations (CO-RE) in the kernel loader.

   - Further the support for BTF_TYPE_TAG annotations.

   - Allow access to local storage in sleepable helpers.

   - Convert verifier argument types to a composable form with different
     attributes which can be shared across types (ro, maybe-null).

   - Prepare libbpf for upcoming v1.0 release by cleaning up APIs,
     creating new, extensible ones where missing and deprecating those
     to be removed.

  Protocols
  ---------

   - WiFi (mac80211/cfg80211):
      - notify user space about long "come back in N" AP responses,
        allow it to react to such temporary rejections
      - allow non-standard VHT MCS 10/11 rates
      - use coarse time in airtime fairness code to save CPU cycles

   - Bluetooth:
      - rework of HCI command execution serialization to use a common
        queue and work struct, and improve handling errors reported in
        the middle of a batch of commands
      - rework HCI event handling to use skb_pull_data, avoiding packet
        parsing pitfalls
      - support AOSP Bluetooth Quality Report

   - SMC:
      - support net namespaces, following the RDMA model
      - improve connection establishment latency by pre-clearing buffers
      - introduce TCP ULP for automatic redirection to SMC

   - Multi-Path TCP:
      - support ioctls: SIOCINQ, OUTQ, and OUTQNSD
      - support socket options: IP_TOS, IP_FREEBIND, IP_TRANSPARENT,
        IPV6_FREEBIND, and IPV6_TRANSPARENT, TCP_CORK and TCP_NODELAY
      - support cmsgs: TCP_INQ
      - improvements in the data scheduler (assigning data to subflows)
      - support fastclose option (quick shutdown of the full MPTCP
        connection, similar to TCP RST in regular TCP)

   - MCTP (Management Component Transport) over serial, as defined by
     DMTF spec DSP0253 - "MCTP Serial Transport Binding".

  Driver API
  ----------

   - Support timestamping on bond interfaces in active/passive mode.

   - Introduce generic phylink link mode validation for drivers which
     don't have any quirks and where MAC capability bits fully express
     what's supported. Allow PCS layer to participate in the validation.
     Convert a number of drivers.

   - Add support to set/get size of buffers on the Rx rings and size of
     the tx copybreak buffer via ethtool.

   - Support offloading TC actions as first-class citizens rather than
     only as attributes of filters, improve sharing and device resource
     utilization.

   - WiFi (mac80211/cfg80211):
      - support forwarding offload (ndo_fill_forward_path)
      - support for background radar detection hardware
      - SA Query Procedures offload on the AP side

  New hardware / drivers
  ----------------------

   - tsnep - FPGA based TSN endpoint Ethernet MAC used in PLCs with
     real-time requirements for isochronous communication with protocols
     like OPC UA Pub/Sub.

   - Qualcomm BAM-DMUX WWAN - driver for data channels of modems
     integrated into many older Qualcomm SoCs, e.g. MSM8916 or MSM8974
     (qcom_bam_dmux).

   - Microchip LAN966x multi-port Gigabit AVB/TSN Ethernet Switch driver
     with support for bridging, VLANs and multicast forwarding
     (lan966x).

   - iwlmei driver for co-operating between Intel's WiFi driver and
     Intel's Active Management Technology (AMT) devices.

   - mse102x - Vertexcom MSE102x Homeplug GreenPHY chips

   - Bluetooth:
      - MediaTek MT7921 SDIO devices
      - Foxconn MT7922A
      - Realtek RTL8852AE

  Drivers
  -------

   - Significantly improve performance in the datapaths of: lan78xx,
     ax88179_178a, lantiq_xrx200, bnxt.

   - Intel Ethernet NICs:
      - igb: support PTP/time PEROUT and EXTTS SDP functions on
        82580/i354/i350 adapters
      - ixgbevf: new PF -> VF mailbox API which avoids the risk of
        mailbox corruption with ESXi
      - iavf: support configuration of VLAN features of finer
        granularity, stacked tags and filtering
      - ice: PTP support for new E822 devices with sub-ns precision
      - ice: support firmware activation without reboot

   - Mellanox Ethernet NICs (mlx5):
      - expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
      - support TC forwarding when tunnel encap and decap happen between
        two ports of the same NIC
      - dynamically size and allow disabling various features to save
        resources for running in embedded / SmartNIC scenarios

   - Broadcom Ethernet NICs (bnxt):
      - use page frag allocator to improve Rx performance
      - expose control over IRQ coalescing mode (CQE vs EQE) via ethtool

   - Other Ethernet NICs:
      - amd-xgbe: add Ryzen 6000 (Yellow Carp) Ethernet support

   - Microsoft cloud/virtual NIC (mana):
      - add XDP support (PASS, DROP, TX)

   - Mellanox Ethernet switches (mlxsw):
      - initial support for Spectrum-4 ASICs
      - VxLAN with IPv6 underlay

   - Marvell Ethernet switches (prestera):
      - support flower flow templates
      - add basic IP forwarding support

   - NXP embedded Ethernet switches (ocelot & felix):
      - support Per-Stream Filtering and Policing (PSFP)
      - enable cut-through forwarding between ports by default
      - support FDMA to improve packet Rx/Tx to CPU

   - Other embedded switches:
      - hellcreek: improve trapping management (STP and PTP) packets
      - qca8k: support link aggregation and port mirroring

   - Qualcomm 802.11ax WiFi (ath11k):
      - qca6390, wcn6855: enable 802.11 power save mode in station mode
      - BSS color change support
      - WCN6855 hw2.1 support
      - 11d scan offload support
      - scan MAC address randomization support
      - full monitor mode, only supported on QCN9074
      - qca6390/wcn6855: report signal and tx bitrate
      - qca6390: rfkill support
      - qca6390/wcn6855: regdb.bin support

   - Intel WiFi (iwlwifi):
      - support SAR GEO Offset Mapping (SGOM) and Time-Aware-SAR (TAS)
        in cooperation with the BIOS
      - support for Optimized Connectivity Experience (OCE) scan
      - support firmware API version 68
      - lots of preparatory work for the upcoming Bz device family

   - MediaTek WiFi (mt76):
      - Specific Absorption Rate (SAR) support
      - mt7921: 160 MHz channel support

   - RealTek WiFi (rtw88):
      - Specific Absorption Rate (SAR) support
      - scan offload

   - Other WiFi NICs
      - ath10k: support fetching (pre-)calibration data from nvmem
      - brcmfmac: configure keep-alive packet on suspend
      - wcn36xx: beacon filter support"

* tag '5.17-net-next' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2048 commits)
  tcp: tcp_send_challenge_ack delete useless param `skb`
  net/qla3xxx: Remove useless DMA-32 fallback configuration
  rocker: Remove useless DMA-32 fallback configuration
  hinic: Remove useless DMA-32 fallback configuration
  lan743x: Remove useless DMA-32 fallback configuration
  net: enetc: Remove useless DMA-32 fallback configuration
  cxgb4vf: Remove useless DMA-32 fallback configuration
  cxgb4: Remove useless DMA-32 fallback configuration
  cxgb3: Remove useless DMA-32 fallback configuration
  bnx2x: Remove useless DMA-32 fallback configuration
  et131x: Remove useless DMA-32 fallback configuration
  be2net: Remove useless DMA-32 fallback configuration
  vmxnet3: Remove useless DMA-32 fallback configuration
  bna: Simplify DMA setting
  net: alteon: Simplify DMA setting
  myri10ge: Simplify DMA setting
  qlcnic: Simplify DMA setting
  net: allwinner: Fix print format
  page_pool: remove spinlock in page_pool_refill_alloc_cache()
  amt: fix wrong return type of amt_send_membership_update()
  ...

cgroup process migration permission checks are performed at write time as
whether a given operation is allowed or not is dependent on the content of
the write - the PID. This currently uses current's cgroup namespace which is
a potential security weakness as it may allow scenarios where a less
privileged process tricks a more privileged one into writing into a fd that
it created.

This patch makes cgroup remember the cgroup namespace at the time of open
and uses it for migration permission checks instad of current's. Note that
this only applies to cgroup2 as cgroup1 doesn't have namespace support.

This also fixes a use-after-free bug on cgroupns reported in

 https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com

Note that backporting this fix also requires the preceding patch.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reported-by: syzbot+50f5cf33a284ce738b62@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com
Fixes: 5136f6365ce3 ("cgroup: implement "nsdelegate" mount option")
Signed-off-by: Tejun Heo <tj@kernel.org>

of->priv is currently used by each interface file implementation to store
private information. This patch collects the current two private data usages
into struct cgroup_file_ctx which is allocated and freed by the common path.
This allows generic private data which applies to multiple files, which will
be used to in the following patch.

Note that cgroup_procs iterator is now embedded as procs.iter in the new
cgroup_file_ctx so that it doesn't need to be allocated and freed
separately.

v2: union dropped from cgroup_file_ctx and the procs iterator is embedded in
    cgroup_file_ctx as suggested by Linus.

v3: Michal pointed out that cgroup1's procs pidlist uses of->priv too.
    Converted. Didn't change to embedded allocation as cgroup1 pidlists get
    stored for caching.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Michal Koutný <mkoutny@suse.com>

cgroup process migration permission checks are performed at write time as
whether a given operation is allowed or not is dependent on the content of
the write - the PID. This currently uses current's credentials which is a
potential security weakness as it may allow scenarios where a less
privileged process tricks a more privileged one into writing into a fd that
it created.

This patch makes both cgroup2 and cgroup1 process migration interfaces to
use the credentials saved at the time of open (file->f_cred) instead of
current's.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Fixes: 187fe84067bd ("cgroup: require write perm on common ancestor when moving processes on the default hierarchy")
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

We're about to break the cgroup-defs.h -> bpf-cgroup.h dependency,
make sure those who actually need more than the definition of
struct cgroup_bpf include bpf-cgroup.h explicitly.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/bpf/20211216025538.1649516-3-kuba@kernel.org

If a cset is already on preloaded list, this means we have already setup
this cset properly for migration.

This patch just relocates the root cgrp lookup which isn't used anyway
when the cset is already on the preloaded list.

[tj@kernel.org: rephrase the commit log]

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>