Pull sound fixes from Takashi Iwai:
 "A collection of lots of small changes, almost all device-specific:

   - A series of fixes for ASoC Qualcomm stuff

   - Various fixes for Cirrus ASoC and HD-audio codecs

   - A few AMD ASoC quirks and usual HD-audio quirks

   - Other misc fixes, including a long-time regression in USB-audio"

* tag 'sound-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (39 commits)
  ASoC: cs35l56: Patch CS35L56_IRQ1_MASK_18 to the default value
  ASoC: meson: axg-fifo: fix irq scheduling issue with PREEMPT_RT
  MAINTAINERS: Update Cirrus Logic parts to linux-sound mailing list
  ASoC: dt-bindings: qcom,wcd939x: Correct reset GPIO polarity in example
  ASoC: dt-bindings: qcom,wcd938x: Correct reset GPIO polarity in example
  ASoC: dt-bindings: qcom,wcd934x: Correct reset GPIO polarity in example
  ASoC: dt-bindings: qcom,wcd937x: Correct reset GPIO polarity in example
  ASoC: amd: yc: Add quirk entry for OMEN by HP Gaming Laptop 16-n0xxx
  ASoC: codecs: ES8326: button detect issue
  ASoC: amd: yc: Support mic on Lenovo Thinkpad E14 Gen 6
  ALSA: usb-audio: Re-add ScratchAmp quirk entries
  ALSA: hda/realtek: Add Framework Laptop 13 (Intel Core Ultra) to quirks
  ALSA: hda/hdmi: Yet more pin fix for HP EliteDesk 800 G4
  ALSA: hda: Add HP MP9 G4 Retail System AMS to force connect list
  ASoC: cs35l56: Handle OTP read latency over SoundWire
  ASoC: codecs: lpass-macro: fix missing codec version
  ALSA: line6: Fix racy access to midibuf
  ASoC: cs-amp-lib: Fix NULL pointer crash if efi.get_variable is NULL
  ASoC: cs35l56: Stop creating ALSA controls for firmware coefficients
  ASoC: wm_adsp: Add control_add callback and export wm_adsp_control_add()
  ...

The recursive aes-arm-bs module load situation reported by Russell King
is getting fixed in the crypto layer, but this in the meantime fixes the
"recursive load hangs forever" by just making the waiting for the first
module load be interruptible.

This should now match the old behavior before commit 9b9879fc
("modules: catch concurrent module loads, treat them as idempotent"),
which used the different "wait for module to be ready" code in
module_patient_check_exists().

End result: a recursive module load will still block, but now a signal
will interrupt it and fail the second module load, at which point the
first module will successfully complete loading.

Fixes: 9b9879fc ("modules: catch concurrent module loads, treat them as idempotent")
Cc: Russell King <linux@armlinux.org.uk>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'asoc-fix-v6.11-rc2' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v6.11

Quite a lot of fixes have come in since the merge window, there's some
repetitive fixes over the Qualcomm drivers increasing the patch count,
along with a large batch of fixes from Cirrus.  We also have some quirks
and some individual fixes.

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bluetooth.

  Current release - regressions:

   - eth: bnxt_en: fix memory out-of-bounds in bnxt_fill_hw_rss_tbl() on
     older chips

  Current release - new code bugs:

   - ethtool: fix off-by-one error / kdoc contradicting the code for max
     RSS context IDs

   - Bluetooth: hci_qca:
      - QCA6390: fix support on non-DT platforms
      - QCA6390: don't call pwrseq_power_off() twice
      - fix a NULL-pointer derefence at shutdown

   - eth: ice: fix incorrect assigns of FEC counters

  Previous releases - regressions:

   - mptcp: fix handling endpoints with both 'signal' and 'subflow'
     flags set

   - virtio-net: fix changing ring count when vq IRQ coalescing not
     supported

   - eth: gve: fix use of netif_carrier_ok() during reconfig / reset

  Previous releases - always broken:

   - eth: idpf: fix bugs in queue re-allocation on reconfig / reset

   - ethtool: fix context creation with no parameters

  Misc:

   - linkwatch: use system_unbound_wq to ease RTNL contention"

* tag 'net-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (41 commits)
  net: dsa: microchip: disable EEE for KSZ8567/KSZ9567/KSZ9896/KSZ9897.
  ethtool: Fix context creation with no parameters
  net: ethtool: fix off-by-one error in max RSS context IDs
  net: pse-pd: tps23881: include missing bitfield.h header
  net: fec: Stop PPS on driver remove
  net: bcmgenet: Properly overlay PHY and MAC Wake-on-LAN capabilities
  l2tp: fix lockdep splat
  net: stmmac: dwmac4: fix PCS duplex mode decode
  idpf: fix UAFs when destroying the queues
  idpf: fix memleak in vport interrupt configuration
  idpf: fix memory leaks and crashes while performing a soft reset
  bnxt_en : Fix memory out-of-bounds in bnxt_fill_hw_rss_tbl()
  net: dsa: bcm_sf2: Fix a possible memory leak in bcm_sf2_mdio_register()
  net/smc: add the max value of fallback reason count
  Bluetooth: hci_sync: avoid dup filtering when passive scanning with adv monitor
  Bluetooth: l2cap: always unlock channel in l2cap_conless_channel()
  Bluetooth: hci_qca: fix a NULL-pointer derefence at shutdown
  Bluetooth: hci_qca: fix QCA6390 support on non-DT platforms
  Bluetooth: hci_qca: don't call pwrseq_power_off() twice for QCA6390
  ice: Fix incorrect assigns of FEC counts
  ...

Pull tracing fixes from Steven Rostedt:

 - Have reading of event format files test if the metadata still exists.

   When a event is freed, a flag (EVENT_FILE_FL_FREED) in the metadata
   is set to state that it is to prevent any new references to it from
   happening while waiting for existing references to close. When the
   last reference closes, the metadata is freed. But the "format" was
   missing a check to this flag (along with some other files) that
   allowed new references to happen, and a use-after-free bug to occur.

 - Have the trace event meta data use the refcount infrastructure
   instead of relying on its own atomic counters.

 - Have tracefs inodes use alloc_inode_sb() for allocation instead of
   using kmem_cache_alloc() directly.

 - Have eventfs_create_dir() return an ERR_PTR instead of NULL as the
   callers expect a real object or an ERR_PTR.

 - Have release_ei() use call_srcu() and not call_rcu() as all the
   protection is on SRCU and not RCU.

 - Fix ftrace_graph_ret_addr() to use the task passed in and not
   current.

 - Fix overflow bug in get_free_elt() where the counter can overflow the
   integer and cause an infinite loop.

 - Remove unused function ring_buffer_nr_pages()

 - Have tracefs freeing use the inode RCU infrastructure instead of
   creating its own.

   When the kernel had randomize structure fields enabled, the rcu field
   of the tracefs_inode was overlapping the rcu field of the inode
   structure, and corrupting it. Instead, use the destroy_inode()
   callback to do the initial cleanup of the code, and then have
   free_inode() free it.

* tag 'trace-v6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracefs: Use generic inode RCU for synchronizing freeing
  ring-buffer: Remove unused function ring_buffer_nr_pages()
  tracing: Fix overflow in get_free_elt()
  function_graph: Fix the ret_stack used by ftrace_graph_ret_addr()
  eventfs: Use SRCU for freeing eventfs_inodes
  eventfs: Don't return NULL in eventfs_create_dir()
  tracefs: Fix inode allocation
  tracing: Use refcount for trace_event_file reference counter
  tracing: Have format file honor EVENT_FILE_FL_FREED

Pull bcachefs fixes from Kent Overstreet:
 "Assorted little stuff:

   - lockdep fixup for lockdep_set_notrack_class()

   - we can now remove a device when using erasure coding without
     deadlocking, though we still hit other issues

   - the 'allocator stuck' timeout is now configurable, and messages are
     ratelimited. The default timeout has been increased from 10 seconds
     to 30"

* tag 'bcachefs-2024-08-08' of git://evilpiepirate.org/bcachefs:
  bcachefs: Use bch2_wait_on_allocator() in btree node alloc path
  bcachefs: Make allocator stuck timeout configurable, ratelimit messages
  bcachefs: Add missing path_traverse() to btree_iter_next_node()
  bcachefs: ec should not allocate from ro devs
  bcachefs: Improved allocator debugging for ec
  bcachefs: Add missing bch2_trans_begin() call
  bcachefs: Add a comment for bucket helper types
  bcachefs: Don't rely on implicit unsigned -> signed integer conversion
  lockdep: Fix lockdep_set_notrack_class() for CONFIG_LOCK_STAT
  bcachefs: Fix double free of ca->buckets_nouse

Device tuning files made with early revision tooling may contain
configuration that can unmask IRQ signals that are owned by the host.

Adding a safe default to the regmap patch ensures that the hardware
matches the driver expectations.
Signed-off-by: Simon Trimmer <simont@opensource.cirrus.com>
Link: https://patch.msgid.link/20240807142648.46932-1-simont@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>

With PREEMPT_RT enabled a spinlock_t becomes a sleeping lock.

This is usually not a problem with spinlocks used in IRQ context since
IRQ handlers get threaded. However, if IRQF_ONESHOT is set, the primary
handler won't be force-threaded and runs always in hardirq context. This is
a problem because spinlock_t requires a preemptible context on PREEMPT_RT.

In this particular instance, regmap mmio uses spinlock_t to protect the
register access and IRQF_ONESHOT is set on the IRQ. In this case, it is
actually better to do everything in threaded handler and it solves the
problem with PREEMPT_RT.
Reported-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Closes: https://lore.kernel.org/linux-amlogic/20240729131652.3012327-1-avkrasnov@salutedevices.comSuggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Fixes: b11d2666 ("ASoC: meson: axg-fifo: use threaded irq to check periods")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20240807162705.4024136-1-jbrunet@baylibre.comSigned-off-by: Mark Brown <broonie@kernel.org>

Now that most kernel work on sound has moved over to the linux-sound
mailing list so should the Cirrus Logic audio parts.
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://patch.msgid.link/20240807140140.421359-1-ckeepax@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>

The reset GPIO of WCD9390/WCD9395 is active low and that's how it is
routed on typical boards, so correct the example DTS to use expected
polarity, instead of IRQ flag (which is a logical mistake on its own).
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20240806114931.40090-4-krzysztof.kozlowski@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

The reset GPIO of WCD9380/WCD9385 is active low and that's how it is
routed on typical boards, so correct the example DTS to use expected
polarity.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20240806114931.40090-3-krzysztof.kozlowski@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

The reset GPIO of WCD9340/WCD9341 is active low and that's how it is
routed on typical boards, so correct the example DTS to use expected
polarity.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20240806114931.40090-2-krzysztof.kozlowski@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

The reset GPIO of WCD9370/WCD9375 is active low and that's how it is
routed on typical boards, so correct the example DTS to use expected
polarity.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20240806114931.40090-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Fix the missing mic on OMEN by HP Gaming Laptop 16-n0xxx by adding the
quirk entry with the board ID 8A44.

Cc: stable@vger.kernel.org
Link: https://bugzilla.suse.com/show_bug.cgi?id=1227182Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20240807170249.16490-1-tiwai@suse.deSigned-off-by: Mark Brown <broonie@kernel.org>

We find that we need to set snd_jack_types to 0. If not,
there will be a probability of button detection errors
Signed-off-by: Zhang Yi <zhangyi@everest-semi.com>
Link: https://patch.msgid.link/20240807025356.24904-2-zhangyi@everest-semi.comSigned-off-by: Mark Brown <broonie@kernel.org>

Lenovo Thinkpad E14 Gen 6 (model type 21M3)
needs a quirk entry for internal mic to work.
Signed-off-by: Krzysztof Stępniak <kfs.szk@gmail.com>
Link: https://patch.msgid.link/20240807001219.1147-1-kfs.szk@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Russell King reported that the arm cbc(aes) crypto module hangs when
loaded, and Herbert Xu bisected it to commit 9b9879fc ("modules:
catch concurrent module loads, treat them as idempotent"), and noted:

 "So what's happening here is that the first modprobe tries to load a
  fallback CBC implementation, in doing so it triggers a load of the
  exact same module due to module aliases.

  IOW we're loading aes-arm-bs which provides cbc(aes). However, this
  needs a fallback of cbc(aes) to operate, which is made out of the
  generic cbc module + any implementation of aes, or ecb(aes). The
  latter happens to also be provided by aes-arm-cb so that's why it
  tries to load the same module again"

So loading the aes-arm-bs module ends up wanting to recursively load
itself, and the recursive load then ends up waiting for the original
module load to complete.

This is a regression, in that it used to be that we just tried to load
the module multiple times, and then as we went on to install it the
second time we would instead just error out because the module name
already existed.

That is actually also exactly what the original "catch concurrent loads"
patch did in commit 9828ed3f ("module: error out early on concurrent
load of the same module file"), but it turns out that it ends up being
racy, in that erroring out before the module has been fully initialized
will cause failures in dependent module loading.

See commit ac2263b5 (which was the revert of that "error out early")
commit for details about why erroring out before the module has been
initialized is actually fundamentally racy.

Now, for the actual recursive module load (as opposed to just
concurrently loading the same module twice), the race is not an issue.

At the same time it's hard for the kernel to see that this is recursion,
because the module load is always done from a usermode helper, so the
recursion is not some simple callchain within the kernel.

End result: this is not the real fix, but this at least adds a warning
for the situation (admittedly much too late for all the debugging pain
that Russell and Herbert went through) and if we can come to a
resolution on how to detect the recursion properly, this re-organizes
the code to make that easier.

Link: https://lore.kernel.org/all/ZrFHLqvFqhzykuYw@shell.armlinux.org.uk/Reported-by: Russell King <linux@armlinux.org.uk>
Debugged-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'loongarch-fixes-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Enable general EFI poweroff method to make poweroff usable on
  hardwares which lack ACPI S5, use accessors to page table entries
  instead of direct dereference to avoid potential problems, and two
  trivial kvm cleanups"

* tag 'loongarch-fixes-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: KVM: Remove undefined a6 argument comment for kvm_hypercall()
  LoongArch: KVM: Remove unnecessary definition of KVM_PRIVATE_MEM_SLOTS
  LoongArch: Use accessors to page table entries instead of direct dereference
  LoongArch: Enable general EFI poweroff method

Tony Nguyen says:

====================
Intel Wired LAN Driver Updates 2024-08-07 (ice)

This series contains updates to ice driver only.

Grzegorz adds IRQ synchronization call before performing reset and
prevents writing to hardware when it is resetting.

Mateusz swaps incorrect assignment of FEC statistics.

* '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue:
  ice: Fix incorrect assigns of FEC counts
  ice: Skip PTP HW writes during PTP reset procedure
  ice: Fix reset handler
====================

Link: https://patch.msgid.link/20240807224521.3819189-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

As noted in the device errata [1-8], EEE support is not fully operational
in the KSZ8567, KSZ9477, KSZ9567, KSZ9896, and KSZ9897 devices, causing
link drops when connected to another device that supports EEE. The patch
series "net: add EEE support for KSZ9477 switch family" merged in commit
9b0bf4f7 caused EEE support to be enabled in these devices. A fix for
this regression for the KSZ9477 alone was merged in commit 08c6d8ba.
This patch extends this fix to the other affected devices.

[1] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/Errata/KSZ8567R-Errata-DS80000752.pdf
[2] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/Errata/KSZ8567S-Errata-DS80000753.pdf
[3] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/Errata/KSZ9477S-Errata-DS80000754.pdf
[4] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/Errata/KSZ9567R-Errata-DS80000755.pdf
[5] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/Errata/KSZ9567S-Errata-DS80000756.pdf
[6] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/Errata/KSZ9896C-Errata-DS80000757.pdf
[7] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/Errata/KSZ9897R-Errata-DS80000758.pdf
[8] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/Errata/KSZ9897S-Errata-DS80000759.pdf

Fixes: 69d3b36c ("net: dsa: microchip: enable EEE support") # for KSZ8567/KSZ9567/KSZ9896/KSZ9897
Link: https://lore.kernel.org/netdev/137ce1ee-0b68-4c96-a717-c8164b514eec@martin-whitaker.me.uk/Signed-off-by: Martin Whitaker <foss@martin-whitaker.me.uk>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Link: https://patch.msgid.link/20240807205209.21464-1-foss@martin-whitaker.me.ukSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The 'at least one change' requirement is not applicable for context
creation, skip the check in such case.
This allows a command such as 'ethtool -X eth0 context new' to work.

The command works by mistake when using older versions of userspace
ethtool due to an incompatibility issue where rxfh.input_xfrm is passed
as zero (unset) instead of RXH_XFRM_NO_CHANGE as done with recent
userspace. This patch does not try to solve the incompatibility issue.

Link: https://lore.kernel.org/netdev/05ae8316-d3aa-4356-98c6-55ed4253c8a7@nvidia.com/
Fixes: 84a1d9c4 ("net: ethtool: extend RXNFC API to support RSS spreading of filter matches")
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Jianbo Liu <jianbol@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Edward Cree <ecree.xilinx@gmail.com>
Link: https://patch.msgid.link/20240807173352.3501746-1-gal@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Both ethtool_ops.rxfh_max_context_id and the default value used when
 it's not specified are supposed to be exclusive maxima (the former
 is documented as such; the latter, U32_MAX, cannot be used as an ID
 since it equals ETH_RXFH_CONTEXT_ALLOC), but xa_alloc() expects an
 inclusive maximum.
Subtract one from 'limit' to produce an inclusive maximum, and pass
 that to xa_alloc().
Increase bnxt's max by one to prevent a (very minor) regression, as
 BNXT_MAX_ETH_RSS_CTX is an inclusive max.  This is safe since bnxt
 is not actually hard-limited; BNXT_MAX_ETH_RSS_CTX is just a
 leftover from old driver code that managed context IDs itself.
Rename rxfh_max_context_id to rxfh_max_num_contexts to make its
 semantics (hopefully) more obvious.

Fixes: 847a8ab1 ("net: ethtool: let the core choose RSS context IDs")
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Link: https://patch.msgid.link/5a2d11a599aa5b0cc6141072c01accfb7758650c.1723045898.git.ecree.xilinx@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Using FIELD_GET() fails in configurations that don't already include
the header file indirectly:

drivers/net/pse-pd/tps23881.c: In function 'tps23881_i2c_probe':
drivers/net/pse-pd/tps23881.c:755:13: error: implicit declaration of function 'FIELD_GET' [-Wimplicit-function-declaration]
  755 |         if (FIELD_GET(TPS23881_REG_DEVID_MASK, ret) != TPS23881_DEVICE_ID) {
      |             ^~~~~~~~~

Fixes: 89108cb5 ("net: pse-pd: tps23881: Fix the device ID check")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20240807075455.2055224-1-arnd@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

PPS was not stopped in `fec_ptp_stop()`, called when
the adapter was removed. Consequentially, you couldn't
safely reload the driver with the PPS signal on.

Fixes: 32cba57b ("net: fec: introduce fec_ptp_stop and use in probe fail path")
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/netdev/CAOMZO5BzcZR8PwKKwBssQq_wAGzVgf1ffwe_nhpQJjviTdxy-w@mail.gmail.com/T/#m01dcb810bfc451a492140f6797ca77443d0cb79fSigned-off-by: Csókás, Bence <csokas.bence@prolan.hu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20240807080956.2556602-1-csokas.bence@prolan.huSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Some Wake-on-LAN modes such as WAKE_FILTER may only be supported by the MAC,
while others might be only supported by the PHY. Make sure that the .get_wol()
returns the union of both rather than only that of the PHY if the PHY supports
Wake-on-LAN.

Fixes: 7e400ff3 ("net: bcmgenet: Add support for PHY-based Wake-on-LAN")
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20240806175659.3232204-1-florian.fainelli@broadcom.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/87sfialu2n.fsf@cloudflare.com/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ #34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c5972 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+6acef9e0a4d1f46c83d4@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: gnault@redhat.com
CC: cong.wang@bytedance.com
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Link: https://patch.msgid.link/20240806160626.1248317-1-jchapman@katalix.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

dwmac4 was decoding the duplex mode from the GMAC_PHYIF_CONTROL_STATUS
register incorrectly, using GMAC_PHYIF_CTRLSTATUS_LNKMOD_MASK (value 1)
rather than GMAC_PHYIF_CTRLSTATUS_LNKMOD (bit 16). Fix this.

Fixes: 70523e63 ("drivers: net: stmmac: reworking the PCS code.")
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1sbJvd-001rGD-E3@rmk-PC.armlinux.org.ukSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Merge tag 'mm-hotfixes-stable-2024-08-07-18-32' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "Nine hotfixes. Five are cc:stable, the others either pertain to
  post-6.10 material or aren't considered necessary for earlier kernels.

  Five are MM and four are non-MM. No identifiable theme here - please
  see the individual changelogs"

* tag 'mm-hotfixes-stable-2024-08-07-18-32' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  padata: Fix possible divide-by-0 panic in padata_mt_helper()
  mailmap: update entry for David Heidelberg
  memcg: protect concurrent access to mem_cgroup_idr
  mm: shmem: fix incorrect aligned index when checking conflicts
  mm: shmem: avoid allocating huge pages larger than MAX_PAGECACHE_ORDER for shmem
  mm: list_lru: fix UAF for memory cgroup
  kcov: properly check for softirq context
  MAINTAINERS: Update LTP members and web
  selftests: mm: add s390 to ARCH check

At the code refactoring of USB-audio quirk handling, I assumed that
the quirk entries of Stanton ScratchAmp devices were only about the
device name, and moved them completely into the rename table.
But it seems that the device requires the quirk entry so that it's
probed by the driver itself.

This re-adds back the quirk entries of ScratchAmp, but in a
minimalistic manner.

Fixes: 5436f59b ("ALSA: usb-audio: Move device rename and profile quirks to an internal table")
Link: https://patch.msgid.link/20240808081803.22300-1-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

Luiz Augusto von Dentz says:

====================
bluetooth pull request for net:

 - hci_sync: avoid dup filtering when passive scanning with adv monitor
 - hci_qca: don't call pwrseq_power_off() twice for QCA6390
 - hci_qca: fix QCA6390 support on non-DT platforms
 - hci_qca: fix a NULL-pointer derefence at shutdown
 - l2cap: always unlock channel in l2cap_conless_channel()

* tag 'for-net-2024-08-07' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
  Bluetooth: hci_sync: avoid dup filtering when passive scanning with adv monitor
  Bluetooth: l2cap: always unlock channel in l2cap_conless_channel()
  Bluetooth: hci_qca: fix a NULL-pointer derefence at shutdown
  Bluetooth: hci_qca: fix QCA6390 support on non-DT platforms
  Bluetooth: hci_qca: don't call pwrseq_power_off() twice for QCA6390
====================

Link: https://patch.msgid.link/20240807210103.142483-1-luiz.dentz@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Tony Nguyen says:

====================
idpf: fix 3 bugs revealed by the Chapter I

Alexander Lobakin says:

The libeth conversion revealed 2 serious issues which lead to sporadic
crashes or WARNs under certain configurations. Additional one was found
while debugging these two with kmemleak.
This one is targeted stable, the rest can be backported manually later
if needed. They can be reproduced only after the conversion is applied
anyway.
====================

Link: https://patch.msgid.link/20240806220923.3359860-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The second tagged commit started sometimes (very rarely, but possible)
throwing WARNs from
net/core/page_pool.c:page_pool_disable_direct_recycling().
Turned out idpf frees interrupt vectors with embedded NAPIs *before*
freeing the queues making page_pools' NAPI pointers lead to freed
memory before these pools are destroyed by libeth.
It's not clear whether there are other accesses to the freed vectors
when destroying the queues, but anyway, we usually free queue/interrupt
vectors only when the queues are destroyed and the NAPIs are guaranteed
to not be referenced anywhere.

Invert the allocation and freeing logic making queue/interrupt vectors
be allocated first and freed last. Vectors don't require queues to be
present, so this is safe. Additionally, this change allows to remove
that useless queue->q_vector pointer cleanup, as vectors are still
valid when freeing the queues (+ both are freed within one function,
so it's not clear why nullify the pointers at all).

Fixes: 1c325aac ("idpf: configure resources for TX queues")
Fixes: 90912f9f ("idpf: convert header split mode to libeth + napi_build_skb()")
Reported-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20240806220923.3359860-4-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The initialization of vport interrupt consists of two functions:
 1) idpf_vport_intr_init() where a generic configuration is done
 2) idpf_vport_intr_req_irq() where the irq for each q_vector is
   requested.

The first function used to create a base name for each interrupt using
"kasprintf()" call. Unfortunately, although that call allocated memory
for a text buffer, that memory was never released.

Fix this by removing creating the interrupt base name in 1).
Instead, always create a full interrupt name in the function 2), because
there is no need to create a base name separately, considering that the
function 2) is never called out of idpf_vport_intr_init() context.

Fixes: d4d55871 ("idpf: initialize interrupts and enable vport")
Cc: stable@vger.kernel.org # 6.7
Signed-off-by: Michal Kubiak <michal.kubiak@intel.com>
Reviewed-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20240806220923.3359860-3-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The second tagged commit introduced a UAF, as it removed restoring
q_vector->vport pointers after reinitializating the structures.
This is due to that all queue allocation functions are performed here
with the new temporary vport structure and those functions rewrite
the backpointers to the vport. Then, this new struct is freed and
the pointers start leading to nowhere.

But generally speaking, the current logic is very fragile. It claims
to be more reliable when the system is low on memory, but in fact, it
consumes two times more memory as at the moment of running this
function, there are two vports allocated with their queues and vectors.
Moreover, it claims to prevent the driver from running into "bad state",
but in fact, any error during the rebuild leaves the old vport in the
partially allocated state.
Finally, if the interface is down when the function is called, it always
allocates a new queue set, but when the user decides to enable the
interface later on, vport_open() allocates them once again, IOW there's
a clear memory leak here.

Just don't allocate a new queue set when performing a reset, that solves
crashes and memory leaks. Readd the old queue number and reopen the
interface on rollback - that solves limbo states when the device is left
disabled and/or without HW queues enabled.

Fixes: 02cbfba1 ("idpf: add ethtool callbacks")
Fixes: e4891e46 ("idpf: split &idpf_queue into 4 strictly-typed queue structures")
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20240806220923.3359860-2-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

A recent commit has modified the code in __bnxt_reserve_rings() to
set the default RSS indirection table to default only when the number
of RX rings is changing.  While this works for newer firmware that
requires RX ring reservations, it causes the regression on older
firmware not requiring RX ring resrvations (BNXT_NEW_RM() returns
false).

With older firmware, RX ring reservations are not required and so
hw_resc->resv_rx_rings is not always set to the proper value.  The
comparison:

if (old_rx_rings != bp->hw_resc.resv_rx_rings)

in __bnxt_reserve_rings() may be false even when the RX rings are
changing.  This will cause __bnxt_reserve_rings() to skip setting
the default RSS indirection table to default to match the current
number of RX rings.  This may later cause bnxt_fill_hw_rss_tbl() to
use an out-of-range index.

We already have bnxt_check_rss_tbl_no_rmgr() to handle exactly this
scenario.  We just need to move it up in bnxt_need_reserve_rings()
to be called unconditionally when using older firmware.  Without the
fix, if the TX rings are changing, we'll skip the
bnxt_check_rss_tbl_no_rmgr() call and __bnxt_reserve_rings() may also
skip the bnxt_set_dflt_rss_indir_tbl() call for the reason explained
in the last paragraph.  Without setting the default RSS indirection
table to default, it causes the regression:

BUG: KASAN: slab-out-of-bounds in __bnxt_hwrm_vnic_set_rss+0xb79/0xe40
Read of size 2 at addr ffff8881c5809618 by task ethtool/31525
Call Trace:
__bnxt_hwrm_vnic_set_rss+0xb79/0xe40
 bnxt_hwrm_vnic_rss_cfg_p5+0xf7/0x460
 __bnxt_setup_vnic_p5+0x12e/0x270
 __bnxt_open_nic+0x2262/0x2f30
 bnxt_open_nic+0x5d/0xf0
 ethnl_set_channels+0x5d4/0xb30
 ethnl_default_set_doit+0x2f1/0x620
Reported-by: Breno Leitao <leitao@debian.org>
Closes: https://lore.kernel.org/netdev/ZrC6jpghA3PWVWSB@gmail.com/
Fixes: 98ba1d93 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()")
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Tested-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20240806053742.140304-1-michael.chan@broadcom.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

bcm_sf2_mdio_register() calls of_phy_find_device() and then
phy_device_remove() in a loop to remove existing PHY devices.
of_phy_find_device() eventually calls bus_find_device(), which calls
get_device() on the returned struct device * to increment the refcount.
The current implementation does not decrement the refcount, which causes
memory leak.

This commit adds the missing phy_device_free() call to decrement the
refcount via put_device() to balance the refcount.

Fixes: 771089c2 ("net: dsa: bcm_sf2: Ensure that MDIO diversion is used")
Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20240806011327.3817861-1-joe@pf.is.s.u-tokyo.ac.jpSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The number of fallback reasons defined in the smc_clc.h file has reached
36. For historical reasons, some are no longer quoted, and there's 33
actually in use. So, add the max value of fallback reason count to 36.

Fixes: 6ac1e656 ("net/smc: support smc v2.x features validate")
Fixes: 7f0620b9 ("net/smc: support max connections per lgr negotiation")
Fixes: 69b888e3 ("net/smc: support max links per lgr negotiation in clc handshake")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Link: https://patch.msgid.link/20240805043856.565677-1-shaozhengchao@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

We are hit with a not easily reproducible divide-by-0 panic in padata.c at
bootup time.

  [   10.017908] Oops: divide error: 0000 1 PREEMPT SMP NOPTI
  [   10.017908] CPU: 26 PID: 2627 Comm: kworker/u1666:1 Not tainted 6.10.0-15.el10.x86_64 #1
  [   10.017908] Hardware name: Lenovo ThinkSystem SR950 [7X12CTO1WW]/[7X12CTO1WW], BIOS [PSE140J-2.30] 07/20/2021
  [   10.017908] Workqueue: events_unbound padata_mt_helper
  [   10.017908] RIP: 0010:padata_mt_helper+0x39/0xb0
    :
  [   10.017963] Call Trace:
  [   10.017968]  <TASK>
  [   10.018004]  ? padata_mt_helper+0x39/0xb0
  [   10.018084]  process_one_work+0x174/0x330
  [   10.018093]  worker_thread+0x266/0x3a0
  [   10.018111]  kthread+0xcf/0x100
  [   10.018124]  ret_from_fork+0x31/0x50
  [   10.018138]  ret_from_fork_asm+0x1a/0x30
  [   10.018147]  </TASK>

Looking at the padata_mt_helper() function, the only way a divide-by-0
panic can happen is when ps->chunk_size is 0.  The way that chunk_size is
initialized in padata_do_multithreaded(), chunk_size can be 0 when the
min_chunk in the passed-in padata_mt_job structure is 0.

Fix this divide-by-0 panic by making sure that chunk_size will be at least
1 no matter what the input parameters are.

Link: https://lkml.kernel.org/r/20240806174647.1050398-1-longman@redhat.com
Fixes: 004ed426 ("padata: add basic support for multithreaded jobs")
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Waiman Long <longman@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Link my old gmail address to my active email.

Link: https://lkml.kernel.org/r/20240804054704.859503-1-david@ixit.czSigned-off-by: David Heidelberg <david@ixit.cz>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Commit 73f576c0 ("mm: memcontrol: fix cgroup creation failure after
many small jobs") decoupled the memcg IDs from the CSS ID space to fix the
cgroup creation failures.  It introduced IDR to maintain the memcg ID
space.  The IDR depends on external synchronization mechanisms for
modifications.  For the mem_cgroup_idr, the idr_alloc() and idr_replace()
happen within css callback and thus are protected through cgroup_mutex
from concurrent modifications.  However idr_remove() for mem_cgroup_idr
was not protected against concurrency and can be run concurrently for
different memcgs when they hit their refcnt to zero.  Fix that.

We have been seeing list_lru based kernel crashes at a low frequency in
our fleet for a long time.  These crashes were in different part of
list_lru code including list_lru_add(), list_lru_del() and reparenting
code.  Upon further inspection, it looked like for a given object (dentry
and inode), the super_block's list_lru didn't have list_lru_one for the
memcg of that object.  The initial suspicions were either the object is
not allocated through kmem_cache_alloc_lru() or somehow
memcg_list_lru_alloc() failed to allocate list_lru_one() for a memcg but
returned success.  No evidence were found for these cases.

Looking more deeply, we started seeing situations where valid memcg's id
is not present in mem_cgroup_idr and in some cases multiple valid memcgs
have same id and mem_cgroup_idr is pointing to one of them.  So, the most
reasonable explanation is that these situations can happen due to race
between multiple idr_remove() calls or race between
idr_alloc()/idr_replace() and idr_remove().  These races are causing
multiple memcgs to acquire the same ID and then offlining of one of them
would cleanup list_lrus on the system for all of them.  Later access from
other memcgs to the list_lru cause crashes due to missing list_lru_one.

Link: https://lkml.kernel.org/r/20240802235822.1830976-1-shakeel.butt@linux.dev
Fixes: 73f576c0 ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>