Leave nested mode before synthesizing shutdown (a.k.a. TRIPLE_FAULT) if
RSM fails when resuming L2 (a.k.a. guest mode).  Architecturally, shutdown
on RSM occurs _before_ the transition back to guest mode on both Intel and
AMD.

On Intel, per the SDM pseudocode, SMRAM state is loaded before critical
VMX state:

  restore state normally from SMRAM;
  ...
  CR4.VMXE := value stored internally;
  IF internal storage indicates that the logical processor had been in
     VMX operation (root or non-root)
  THEN
     enter VMX operation (root or non-root);
     restore VMX-critical state as defined in Section 32.14.1;
     ...
     restore current VMCS pointer;
  FI;

AMD's APM is both less clearcut and more explicit.  Because AMD CPUs save
VMCB and guest state in SMRAM itself, given the lack of anything in the
APM to indicate a shutdown in guest mode is possible, a straightforward
reading of the clause on invalid state is that _what_ state is invalid is
irrelevant, i.e. all roads lead to shutdown.

  An RSM causes a processor shutdown if an invalid-state condition is
  found in the SMRAM state-save area.

This fixes a bug found by syzkaller where synthesizing shutdown for L2
led to a nested VM-Exit (if L1 is intercepting shutdown), which in turn
caused KVM to complain about trying to cancel a nested VM-Enter (see
commit 759cbd59 ("KVM: x86: nSVM/nVMX: set nested_run_pending on VM
entry which is a result of RSM").

Note, Paolo pointed out that KVM shouldn't set nested_run_pending until
after loading SMRAM state.  But as above, that's only half the story, KVM
shouldn't transition to guest mode either.  Unfortunately, fixing that
mess requires rewriting the nVMX and nSVM RSM flows to not piggyback
their nested VM-Enter flows, as executing the nested VM-Enter flows after
loading state from SMRAM would clobber much of said state.

For now, add a FIXME to call out that transitioning to guest mode before
loading state from SMRAM is wrong.

Link: https://lore.kernel.org/all/CABgObfYaUHXyRmsmg8UjRomnpQ0Jnaog9-L2gMjsjkqChjDYUQ@mail.gmail.com
Reported-by: syzbot+988d9efcdf137bc05f66@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/0000000000007a9acb06151e1670@google.comReported-by: Zheyu Ma <zheyuma97@gmail.com>
Closes: https://lore.kernel.org/all/CAMhUBjmXMYsEoVYw_M8hSZjBMHh24i88QYm-RY6HDta5YZ7Wgw@mail.gmail.comAnalyzed-by: Michal Wilczynski <michal.wilczynski@intel.com>
Cc: Kishen Maloor <kishen.maloor@intel.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20240906161337.1118412-1-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add a fastpath for HLT VM-Exits by immediately re-entering the guest if
it has a pending wake event.  When virtual interrupt delivery is enabled,
i.e. when KVM doesn't need to manually inject interrupts, this allows KVM
to stay in the fastpath run loop when a vIRQ arrives between the guest
doing CLI and STI;HLT.  Without AMD's Idle HLT-intercept support, the CPU
generates a HLT VM-Exit even though KVM will immediately resume the guest.

Note, on bare metal, it's relatively uncommon for a modern guest kernel to
actually trigger this scenario, as the window between the guest checking
for a wake event and committing to HLT is quite small.  But in a nested
environment, the timings change significantly, e.g. rudimentary testing
showed that ~50% of HLT exits where HLT-polling was successful would be
serviced by this fastpath, i.e. ~50% of the time that a nested vCPU gets
a wake event before KVM schedules out the vCPU, the wake event was pending
even before the VM-Exit.

Link: https://lore.kernel.org/all/20240528041926.3989-3-manali.shukla@amd.com
Link: https://lore.kernel.org/r/20240802195120.325560-6-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Shuffle code around in x86.c so that the various helpers related to vCPU
blocking/running logic are (a) located near each other and (b) ordered so
that HLT emulation can use kvm_vcpu_has_events() in a future path.

No functional change intended.

Link: https://lore.kernel.org/r/20240802195120.325560-5-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Exit to userspace if a fastpath handler triggers such an exit, which can
happen when skipping the instruction, e.g. due to userspace
single-stepping the guest via KVM_GUESTDBG_SINGLESTEP or because of an
emulation failure.

Fixes: 404d5d7b ("KVM: X86: Introduce more exit_fastpath_completion enum values")
Link: https://lore.kernel.org/r/20240802195120.325560-4-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Now that the WRMSR fastpath for x2APIC_ICR and TSC_DEADLINE are identical,
ignoring the backend MSR handling, consolidate the common bits of skipping
the instruction and setting the return value.

No functional change intended.

Link: https://lore.kernel.org/r/20240802195120.325560-3-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Re-enter the guest in the fastpath if WRMSR emulation for x2APIC's ICR is
successful, as no additional work is needed, i.e. there is no code unique
for WRMSR exits between the fastpath and the "!= EXIT_FASTPATH_NONE" check
in __vmx_handle_exit().

Link: https://lore.kernel.org/r/20240802195120.325560-2-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

When AVIC, and thus IPI virtualization on AMD, is enabled, the CPU will
virtualize ICR writes.  Unfortunately, the CPU doesn't do a very good job,
as it fails to clear the BUSY bit and also allows writing ICR2[23:0],
despite them being "RESERVED MBZ".  Account for the quirky behavior in
the xapic_state test to avoid failures in a configuration that likely has
no hope of ever being enabled in production.

Link: https://lore.kernel.org/r/20240719235107.3023592-11-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Now that the BUSY bit mess is gone (for x2APIC), verify that the *guest*
can read back the ICR value that it wrote.  Due to the divergent
behavior between AMD and Intel with respect to the backing storage of the
ICR in the vAPIC page, emulating a seemingly simple MSR write is quite
complex.

Link: https://lore.kernel.org/r/20240719235107.3023592-10-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Actually test x2APIC ICR reserved bits instead of deliberately skipping
them.  The behavior that is observed when IPI virtualization is enabled is
the architecturally correct behavior, KVM is the one who was wrong, i.e.
KVM was missing reserved bit checks.

Fixes: 4b88b1a5 ("KVM: selftests: Enhance handling WRMSR ICR register in x2APIC mode")
Link: https://lore.kernel.org/r/20240719235107.3023592-9-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Don't test the ICR BUSY bit when x2APIC is enabled as AMD and Intel have
different behavior (AMD #GPs, Intel ignores), and the fact that the CPU
performs the reserved bit checks when IPI virtualization is enabled makes
it impossible for KVM to precisely emulate one or the other.

Link: https://lore.kernel.org/r/20240719235107.3023592-8-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add helpers to allow and expect #GP on x2APIC MSRs, and opportunistically
have the existing helper spit out a more useful error message if an
unexpected exception occurs.

Link: https://lore.kernel.org/r/20240719235107.3023592-7-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Now that selftests support printf() in the guest, report unexpected
exceptions via the regular assertion framework.  Exceptions were special
cased purely to provide a better error message.  Convert only x86 for now,
as it's low-hanging fruit (already formats the assertion in the guest),
and converting x86 will allow adding asserts in x86 library code without
needing to update multiple tests.

Once all other architectures are converted, this will allow moving the
reporting to common code, which will in turn allow adding asserts in
common library code, and will also allow removing UCALL_UNHANDLED.

Link: https://lore.kernel.org/r/20240719235107.3023592-6-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Open code a version of vcpu_run() in the guest_printf test in anticipation
of adding UCALL_ABORT handling to _vcpu_run().  The guest_printf test
intentionally generates asserts to verify the output, and thus needs to
bypass common assert handling.

Open code a helper in the guest_printf test, as it's not expected that any
other test would want to skip _only_ the UCALL_ABORT handling.

Link: https://lore.kernel.org/r/20240719235107.3023592-5-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Re-introduce the "split" x2APIC ICR storage that KVM used prior to Intel's
IPI virtualization support, but only for AMD.  While not stated anywhere
in the APM, despite stating the ICR is a single 64-bit register, AMD CPUs
store the 64-bit ICR as two separate 32-bit values in ICR and ICR2.  When
IPI virtualization (IPIv on Intel, all AVIC flavors on AMD) is enabled,
KVM needs to match CPU behavior as some ICR ICR writes will be handled by
the CPU, not by KVM.

Add a kvm_x86_ops knob to control the underlying format used by the CPU to
store the x2APIC ICR, and tune it to AMD vs. Intel regardless of whether
or not x2AVIC is enabled.  If KVM is handling all ICR writes, the storage
format for x2APIC mode doesn't matter, and having the behavior follow AMD
versus Intel will provide better test coverage and ease debugging.

Fixes: 4d1d7942 ("KVM: SVM: Introduce logic to (de)activate x2AVIC mode")
Cc: stable@vger.kernel.org
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20240719235107.3023592-4-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Hoist kvm_x2apic_icr_write() above kvm_apic_write_nodecode() so that a
local helper to _read_ the x2APIC ICR can be added and used in the
nodecode path without needing a forward declaration.

No functional change intended.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240719235107.3023592-3-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Inject a #GP on a WRMSR(ICR) that attempts to set any reserved bits that
are must-be-zero on both Intel and AMD, i.e. any reserved bits other than
the BUSY bit, which Intel ignores and basically says is undefined.

KVM's xapic_state_test selftest has been fudging the bug since commit
4b88b1a5 ("KVM: selftests: Enhance handling WRMSR ICR register in
x2APIC mode"), which essentially removed the testcase instead of fixing
the bug.

WARN if the nodecode path triggers a #GP, as the CPU is supposed to check
reserved bits for ICR when it's partially virtualized.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240719235107.3023592-2-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Extend KVM's suppression of userspace MSR access failures to MSRs that KVM
reports as emulated, but are ultimately unsupported, e.g. if the VMX MSRs
are emulated by KVM, but are unsupported given the vCPU model.
Suggested-by: Weijiang Yang <weijiang.yang@intel.com>
Reviewed-by: Weijiang Yang <weijiang.yang@intel.com>
Link: https://lore.kernel.org/r/20240802181935.292540-11-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Extend KVM's suppression of failures due to a userspace access to an
unsupported, but advertised as a "to save" MSR to all MSRs, not just those
that happen to reach the default case statements in kvm_get_msr_common()
and kvm_set_msr_common().  KVM's soon-to-be-established ABI is that if an
MSR is advertised to userspace, then userspace is allowed to read the MSR,
and write back the value that was read, i.e. why an MSR is unsupported
doesn't change KVM's ABI.

Practically speaking, this is very nearly a nop, as the only other paths
that return KVM_MSR_RET_UNSUPPORTED are {svm,vmx}_get_feature_msr(), and
it's unlikely, though not impossible, that userspace is using KVM_GET_MSRS
on unsupported MSRs.

The primary goal of moving the suppression to common code is to allow
returning KVM_MSR_RET_UNSUPPORTED as appropriate throughout KVM, without
having to manually handle the "is userspace accessing an advertised"
waiver.  I.e. this will allow formalizing KVM's ABI without incurring a
high maintenance cost.

Link: https://lore.kernel.org/r/20240802181935.292540-10-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Move the definitions of the various MSR arrays above kvm_do_msr_access()
so that kvm_do_msr_access() can query the arrays when handling failures,
e.g. to squash errors if userspace tries to read an MSR that isn't fully
supported, but that KVM advertised as being an MSR-to-save.

No functional change intended.

Link: https://lore.kernel.org/r/20240802181935.292540-9-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add a common helper, kvm_do_msr_access(), to invoke the "leaf" APIs that
are type and access specific, and more importantly to handle errors that
are returned from the leaf APIs.  I.e. turn kvm_msr_ignored_check() from a
a helper that is called on an error, into a trampoline that detects errors
*and* applies relevant side effects, e.g. logging unimplemented accesses.

Because the leaf APIs are used for guest accesses, userspace accesses, and
KVM accesses, and because KVM supports restricting access to MSRs from
userspace via filters, the error handling is subtly non-trivial.  E.g. KVM
has had at least one bug escape due to making each "outer" function handle
errors.  See commit 3376ca3f ("KVM: x86: Fix KVM_GET_MSRS stack info
leak").

Link: https://lore.kernel.org/r/20240802181935.292540-8-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Refactor kvm_get_feature_msr() to take the components of kvm_msr_entry as
separate parameters, along with a vCPU pointer, i.e. to give it the same
prototype as kvm_{g,s}et_msr_ignored_check().  This will allow using a
common inner helper for handling accesses to "regular" and feature MSRs.

No functional change intended.

Link: https://lore.kernel.org/r/20240802181935.292540-7-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Rename all APIs related to feature MSRs from get_msr_feature() to
get_feature_msr().  The APIs get "feature MSRs", not "MSR features".
And unlike kvm_{g,s}et_msr_common(), the "feature" adjective doesn't
describe the helper itself.

No functional change intended.

Link: https://lore.kernel.org/r/20240802181935.292540-6-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Refactor get_msr_feature() to take the index and data pointer as distinct
parameters in anticipation of eliminating "struct kvm_msr_entry" usage
further up the primary callchain.

No functional change intended.

Link: https://lore.kernel.org/r/20240802181935.292540-5-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Rename the "INVALID" internal MSR error return code to "UNSUPPORTED" to
try and make it more clear that access was denied because the MSR itself
is unsupported/unknown.  "INVALID" is too ambiguous, as it could just as
easily mean the value for WRMSR as invalid.

Avoid UNKNOWN and UNIMPLEMENTED, as the error code is used for MSRs that
_are_ actually implemented by KVM, e.g. if the MSR is unsupported because
an associated feature flag is not present in guest CPUID.

Opportunistically beef up the comments for the internal MSR error codes.

Link: https://lore.kernel.org/r/20240802181935.292540-4-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Move VMX's MSR_TYPE_{R,W,RW} #defines to x86.h, as enums, so that they can
be used by common x86 code, e.g. instead of doing "bool write".

Opportunistically tweak the definitions to make it more obvious that the
values are bitmasks, not arbitrary ascending values.

No functional change intended.

Link: https://lore.kernel.org/r/20240802181935.292540-3-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Inject a #GP if the guest attempts to change MSR_AMD64_DE_CFG from its
*current* value, not if the guest attempts to write a value other than
KVM's set of supported bits.  As per the comment and the changelog of the
original code, the intent is to effectively make MSR_AMD64_DE_CFG read-
only for the guest.

Opportunistically use a more conventional equality check instead of an
exclusive-OR check to detect attempts to change bits.

Fixes: d1d93fa9 ("KVM: SVM: Add MSR-based feature support for serializing LFENCE")
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240802181935.292540-2-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Use this_cpu_ptr() instead of open coding the equivalent in
kvm_user_return_msr_cpu_online.
Signed-off-by: Li Chen <chenl311@chinatelecom.cn>
Link: https://lore.kernel.org/r/87zfp96ojk.wl-me@linux.beautySigned-off-by: Sean Christopherson <seanjc@google.com>

Advertise AVX10.1 related CPUIDs, i.e. report AVX10 support bit via
CPUID.(EAX=07H, ECX=01H):EDX[bit 19] and new CPUID leaf 0x24H so that
guest OS and applications can query the AVX10.1 CPUIDs directly. Intel
AVX10 represents the first major new vector ISA since the introduction of
Intel AVX512, which will establish a common, converged vector instruction
set across all Intel architectures[1].

AVX10.1 is an early version of AVX10, that enumerates the Intel AVX512
instruction set at 128, 256, and 512 bits which is enabled on
Granite Rapids. I.e., AVX10.1 is only a new CPUID enumeration with no
new functionality.   New features, e.g. Embedded Rounding and Suppress
All Exceptions (SAE) will be introduced in AVX10.2.

Advertising AVX10.1 is safe because there is nothing to enable for AVX10.1,
i.e. it's purely a new way to enumerate support, thus there will never be
anything for the kernel to enable. Note just the CPUID checking is changed
when using AVX512 related instructions, e.g. if using one AVX512
instruction needs to check (AVX512 AND AVX512DQ), it can check
((AVX512 AND AVX512DQ) OR AVX10.1) after checking XCR0[7:5].

The versions of AVX10 are expected to be inclusive, e.g. version N+1 is
a superset of version N. Per the spec, the version can never be 0, just
advertise AVX10.1 if it's supported in hardware. Moreover, advertising
AVX10_{128,256,512} needs to land in the same commit as advertising basic
AVX10.1 support, otherwise KVM would advertise an impossible CPU model.
E.g. a CPU with AVX512 but not AVX10.1/512 is impossible per the SDM.

As more and more AVX related CPUIDs are added (it would have resulted in
around 40-50 CPUID flags when developing AVX10), the versioning approach
is introduced. But incrementing version numbers are bad for virtualization.
E.g. if AVX10.2 has a feature that shouldn't be enumerated to guests for
whatever reason, then KVM can't enumerate any "later" features either,
because the only way to hide the problematic AVX10.2 feature is to set the
version to AVX10.1 or lower[2]. But most AVX features are just passed
through and don't have virtualization controls, so AVX10 should not be
problematic in practice, so long as Intel honors their promise that future
versions will be supersets of past versions.

[1] https://cdrdv2.intel.com/v1/dl/getContent/784267
[2] https://lore.kernel.org/all/Zkz5Ak0PQlAN8DxK@google.com/Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Link: https://lore.kernel.org/r/20240819062327.3269720-1-tao1.su@linux.intel.com
[sean: minor changelog tweaks]
Signed-off-by: Sean Christopherson <seanjc@google.com>

Change the data type of the local variable this_tsc_khz to u32 because
virtual_tsc_khz is also declared as u32.

Since do_div() casts the divisor to u32 anyway, changing the data type
of this_tsc_khz to u32 also removes the following Coccinelle/coccicheck
warning reported by do_div.cocci:

  WARNING: do_div() does a 64-by-32 division, please consider using div64_ul instead
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Link: https://lore.kernel.org/r/20240814203345.2234-2-thorsten.blum@toblux.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Merge tag 'driver-core-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are two driver fixes for regressions from 6.11-rc1 due to the
  driver core change making a structure in a driver core callback const.

  These were missed by all testing EXCEPT for what Bart happened to be
  running, so I appreciate the fixes provided here for some
  odd/not-often-used driver subsystems that nothing else happened to
  catch.

  Both of these fixes have been in linux-next all week with no reported
  issues"

* tag 'driver-core-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  mips: sgi-ip22: Fix the build
  ARM: riscpc: ecard: Fix the build

Pull char / misc fixes from Greg KH:
 "Here are some small char/misc fixes for 6.11-rc4 to resolve reported
  problems. Included in here are:

   - fastrpc revert of a change that broke userspace

   - xillybus fixes for reported issues

  Half of these have been in linux-next this week with no reported
  problems, I don't know if the last bit of xillybus driver changes made
  it in, but they are 'obviously correct' so will be safe :)"

* tag 'char-misc-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  char: xillybus: Check USB endpoints when probing device
  char: xillybus: Refine workqueue handling
  Revert "misc: fastrpc: Restrict untrusted app to attach to privileged PD"
  char: xillybus: Don't destroy workqueue from work item running on it

Pull tty / serial fixes from Greg KH:
 "Here are some small tty and serial driver fixes for 6.11-rc4 to
  resolve some reported problems. Included in here are:

   - conmakehash.c userspace build issues

   - fsl_lpuart driver fix

   - 8250_omap revert for reported regression

   - atmel_serial rts flag fix

  All of these have been in linux-next this week with no reported
  issues"

* tag 'tty-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "serial: 8250_omap: Set the console genpd always on if no console suspend"
  tty: atmel_serial: use the correct RTS flag.
  tty: vt: conmakehash: remove non-portable code printing comment header
  tty: serial: fsl_lpuart: mark last busy before uart_add_one_port

Pull USB / Thunderbolt driver fixes from Greg KH:
 "Here are some small USB and Thunderbolt driver fixes for 6.11-rc4 to
  resolve some reported issues. Included in here are:

   - thunderbolt driver fixes for reported problems

   - typec driver fixes

   - xhci fixes

   - new device id for ljca usb driver

  All of these have been in linux-next this week with no reported
  issues"

* tag 'usb-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  xhci: Fix Panther point NULL pointer deref at full-speed re-enumeration
  usb: misc: ljca: Add Lunar Lake ljca GPIO HID to ljca_gpio_hids[]
  Revert "usb: typec: tcpm: clear pd_event queue in PORT_RESET"
  usb: typec: ucsi: Fix the return value of ucsi_run_command()
  usb: xhci: fix duplicate stall handling in handle_tx_event()
  usb: xhci: Check for xhci->interrupters being allocated in xhci_mem_clearup()
  thunderbolt: Mark XDomain as unplugged when router is removed
  thunderbolt: Fix memory leaks in {port|retimer}_sb_regs_write()

Pull more btrfs fixes from David Sterba:
 "A more fixes. We got reports that shrinker added in 6.10 still causes
  latency spikes and the fixes don't handle all corner cases. Due to
  summer holidays we're taking a shortcut to disable it for release
  builds and will fix it in the near future.

   - only enable extent map shrinker for DEBUG builds, temporary quick
     fix to avoid latency spikes for regular builds

   - update target inode's ctime on unlink, mandated by POSIX

   - properly take lock to read/update block group's zoned variables

   - add counted_by() annotations"

* tag 'for-6.11-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: only enable extent map shrinker for DEBUG builds
  btrfs: zoned: properly take lock to read/update block group's zoned variables
  btrfs: tree-checker: add dev extent item checks
  btrfs: update target inode's ctime on unlink
  btrfs: send: annotate struct name_cache_entry with __counted_by()

fuse_notify_store(), unlike fuse_do_readpage(), does not enable page
zeroing (because it can be used to change partial page contents).

So fuse_notify_store() must be more careful to fully initialize page
contents (including parts of the page that are beyond end-of-file)
before marking the page uptodate.

The current code can leave beyond-EOF page contents uninitialized, which
makes these uninitialized page contents visible to userspace via mmap().

This is an information leak, but only affects systems which do not
enable init-on-alloc (via CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y or the
corresponding kernel command line parameter).

Link: https://bugs.chromium.org/p/project-zero/issues/detail?id=2574
Cc: stable@kernel.org
Fixes: a1d75f25 ("fuse: add store request")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'mm-hotfixes-stable-2024-08-17-19-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "16 hotfixes. All except one are for MM. 10 of these are cc:stable and
  the others pertain to post-6.10 issues.

  As usual with these merges, singletons and doubletons all over the
  place, no identifiable-by-me theme. Please see the lovingly curated
  changelogs to get the skinny"

* tag 'mm-hotfixes-stable-2024-08-17-19-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/migrate: fix deadlock in migrate_pages_batch() on large folios
  alloc_tag: mark pages reserved during CMA activation as not tagged
  alloc_tag: introduce clear_page_tag_ref() helper function
  crash: fix riscv64 crash memory reserve dead loop
  selftests: memfd_secret: don't build memfd_secret test on unsupported arches
  mm: fix endless reclaim on machines with unaccepted memory
  selftests/mm: compaction_test: fix off by one in check_compaction()
  mm/numa: no task_numa_fault() call if PMD is changed
  mm/numa: no task_numa_fault() call if PTE is changed
  mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0
  mm/memory-failure: use raw_spinlock_t in struct memory_failure_cpu
  mm: don't account memmap per-node
  mm: add system wide stats items category
  mm: don't account memmap on failure
  mm/hugetlb: fix hugetlb vs. core-mm PT locking
  mseal: fix is_madv_discard()

Pull powerpc fixes from Michael Ellerman:

 - Fix crashes on 85xx with some configs since the recent hugepd rework.

 - Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUAL on some
   platforms.

 - Don't enable offline cores when changing SMT modes, to match existing
   userspace behaviour.

Thanks to Christophe Leroy, Dr. David Alan Gilbert, Guenter Roeck, Nysal
Jan K.A, Shrikanth Hegde, Thomas Gleixner, and Tyrel Datwyler.

* tag 'powerpc-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/topology: Check if a core is online
  cpu/SMT: Enable SMT only if a core is online
  powerpc/mm: Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUAL
  powerpc/mm: Fix size of allocated PGDIR
  soc: fsl: qbman: remove unused struct 'cgr_comp'

Pull smb client fixes from Steve French:

 - fix for clang warning - additional null check

 - fix for cached write with posix locks

 - flexible structure fix

* tag 'v6.11-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb: smb2pdu.h: Use static_assert() to check struct sizes
  smb3: fix lock breakage for cached writes
  smb/client: avoid possible NULL dereference in cifs_free_subrequest()

Pull i2c fixes from Wolfram Sang:
 "I2C core fix replacing IS_ENABLED() with IS_REACHABLE()

  For host drivers, there are two fixes:

   - Tegra I2C Controller: Addresses a potential double-locking issue
     during probe. ACPI devices are not IRQ-safe when invoking runtime
     suspend and resume functions, so the irq_safe flag should not be
     set.

   - Qualcomm GENI I2C Controller: Fixes an oversight in the exit path
     of the runtime_resume() function, which was missed in the previous
     release"

* tag 'i2c-for-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: tegra: Do not mark ACPI devices as irq safe
  i2c: Use IS_REACHABLE() for substituting empty ACPI functions
  i2c: qcom-geni: Add missing geni_icc_disable in geni_i2c_runtime_resume