Pull xen netback buffer overflow fix from Juergen Gross:
 "The fix for XSA-423 added logic to Linux'es netback driver to deal
  with a frontend splitting a packet in a way such that not all of the
  headers would come in one piece.

  Unfortunately the logic introduced there didn't account for the
  extreme case of the entire packet being split into as many pieces as
  permitted by the protocol, yet still being smaller than the area
  that's specially dealt with to keep all (possible) headers together.

  Such an unusual packet would therefore trigger a buffer overrun in the
  driver"

* tag 'xsa432-6.5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/netback: Fix buffer overrun triggered by unusual packet

Pull x86/gds fixes from Dave Hansen:
 "Mitigate Gather Data Sampling issue:

   - Add Base GDS mitigation

   - Support GDS_NO under KVM

   - Fix a documentation typo"

* tag 'gds-for-linus-2023-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation/x86: Fix backwards on/off logic about YMM support
  KVM: Add GDS_NO support to KVM
  x86/speculation: Add Kconfig option for GDS
  x86/speculation: Add force option to GDS mitigation
  x86/speculation: Add Gather Data Sampling mitigation

Pull x86/srso fixes from Borislav Petkov:
 "Add a mitigation for the speculative RAS (Return Address Stack)
  overflow vulnerability on AMD processors.

  In short, this is yet another issue where userspace poisons a
  microarchitectural structure which can then be used to leak privileged
  information through a side channel"

* tag 'x86_bugs_srso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/srso: Tie SBPB bit setting to microcode patch detection
  x86/srso: Add a forgotten NOENDBR annotation
  x86/srso: Fix return thunks in generated code
  x86/srso: Add IBPB on VMEXIT
  x86/srso: Add IBPB
  x86/srso: Add SRSO_NO support
  x86/srso: Add IBPB_BRTYPE support
  x86/srso: Add a Speculative RAS Overflow mitigation
  x86/bugs: Increase the x86 bugs vector size to two u32s

Pull workqueue fixes from Tejun Heo:

 - The recently added cpu_intensive auto detection and warning mechanism
   was spuriously triggered on slow CPUs.

   While not causing serious issues, it's still a nuisance and can cause
   unintended concurrency management behaviors.

   Relax the threshold on machines with lower BogoMIPS. While BogoMIPS
   is not an accurate measure of performance by most measures, we don't
   have to be accurate and it has rough but strong enough correlation.

 - A correction in Kconfig help text

* tag 'wq-for-6.5-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Scale up wq_cpu_intensive_thresh_us if BogoMIPS is below 4000
  workqueue: Fix cpu_intensive_thresh_us name in help text

Pull tpm fixes from Jarkko Sakkinen:
 "A few more bug fixes"

* tag 'tpmdd-v6.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd:
  tpm/tpm_tis: Disable interrupts for Lenovo P620 devices
  tpm: Disable RNG for all AMD fTPMs
  sysctl: set variable key_sysctls storage-class-specifier to static
  tpm/tpm_tis: Disable interrupts for TUXEDO InfinityBook S 15/17 Gen7

The Lenovo ThinkStation P620 suffers from an irq storm issue like various
other Lenovo machines, so add an entry for it to tpm_tis_dmi_table and
force polling.

It is worth noting that 481c2d14 (tpm,tpm_tis: Disable interrupts after
1000 unhandled IRQs) does not seem to fix the problem on this machine, but
setting 'tpm_tis.interrupts=0' on the kernel command line does.

[jarkko@kernel.org: truncated the commit ID in the description to 12
characters]
Cc: stable@vger.kernel.org # v6.4+
Fixes: e644b2f4 ("tpm, tpm_tis: Enable interrupt test")
Signed-off-by: Jonathan McDowell <noodles@meta.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

The TPM RNG functionality is not necessary for entropy when the CPU
already supports the RDRAND instruction. The TPM RNG functionality
was previously disabled on a subset of AMD fTPM series, but reports
continue to show problems on some systems causing stutter root caused
to TPM RNG functionality.

Expand disabling TPM RNG use for all AMD fTPMs whether they have versions
that claim to have fixed or not. To accomplish this, move the detection
into part of the TPM CRB registration and add a flag indicating that
the TPM should opt-out of registration to hwrng.

Cc: stable@vger.kernel.org # 6.1.y+
Fixes: b006c439 ("hwrng: core - start hwrng kthread also for untrusted sources")
Fixes: f1324bbc ("tpm: disable hwrng for fTPM on some AMD designs")
Reported-by: daniil.stas@posteo.net
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217719
Reported-by: bitlord0xff@gmail.com
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217212Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

smatch reports
security/keys/sysctl.c:12:18: warning: symbol
  'key_sysctls' was not declared. Should it be static?

This variable is only used in its defining file, so it should be static.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

TUXEDO InfinityBook S 15/17 Gen7 suffers from an IRQ problem on
tpm_tis like a few other laptops.  Add an entry for the workaround.

Cc: stable@vger.kernel.org
Fixes: e644b2f4 ("tpm, tpm_tis: Enable interrupt test")
Link: https://bugzilla.suse.com/show_bug.cgi?id=1213645Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

Pull kvm fixes from Paolo Bonzini:
 "x86:

   - Fix SEV race condition

  ARM:

   - Fixes for the configuration of SVE/SME traps when hVHE mode is in
     use

   - Allow use of pKVM on systems with FF-A implementations that are
     v1.0 compatible

   - Request/release percpu IRQs (arch timer, vGIC maintenance)
     correctly when pKVM is in use

   - Fix function prototype after __kvm_host_psci_cpu_entry() rename

   - Skip to the next instruction when emulating writes to TCR_EL1 on
     AmpereOne systems

  Selftests:

   - Fix missing include"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  selftests/rseq: Fix build with undefined __weak
  KVM: SEV: remove ghcb variable declarations
  KVM: SEV: only access GHCB fields once
  KVM: SEV: snapshot the GHCB before accessing it
  KVM: arm64: Skip instruction after emulating write to TCR_EL1
  KVM: arm64: fix __kvm_host_psci_cpu_entry() prototype
  KVM: arm64: Fix resetting SME trap values on reset for (h)VHE
  KVM: arm64: Fix resetting SVE trap values on reset for hVHE
  KVM: arm64: Use the appropriate feature trap register when activating traps
  KVM: arm64: Helper to write to appropriate feature trap register based on mode
  KVM: arm64: Disable SME traps for (h)VHE at setup
  KVM: arm64: Use the appropriate feature trap register for SVE at EL2 setup
  KVM: arm64: Factor out code for checking (h)VHE mode into a macro
  KVM: arm64: Rephrase percpu enable/disable tracking in terms of hyp
  KVM: arm64: Fix hardware enable/disable flows for pKVM
  KVM: arm64: Allow pKVM on v1.0 compatible FF-A implementations

Pull MMC fixes from Ulf Hansson:

 - moxart: Fix big-endian conversion for SCR structure

 - sdhci-f-sdh30: Replace with sdhci_pltfm to fix PM support

* tag 'mmc-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: sdhci-f-sdh30: Replace with sdhci_pltfm
  mmc: moxart: read scr register without changing byte order

The SBPB bit in MSR_IA32_PRED_CMD is supported only after a microcode
patch has been applied so set X86_FEATURE_SBPB only then. Otherwise,
guests would attempt to set that bit and #GP on the MSR write.

While at it, make SMT detection more robust as some guests - depending
on how and what CPUID leafs their report - lead to cpu_smt_control
getting set to CPU_SMT_NOT_SUPPORTED but SRSO_NO should be set for any
guest incarnation where one simply cannot do SMT, for whatever reason.

Fixes: fb3bd914 ("x86/srso: Add a Speculative RAS Overflow mitigation")
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reported-by: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>

Pull vfs fixes from Christian Brauner:

 - Fix a wrong check for O_TMPFILE during RESOLVE_CACHED lookup

 - Clean up directory iterators and clarify file_needs_f_pos_lock()

* tag 'v6.5-rc5.vfs.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fs: rely on ->iterate_shared to determine f_pos locking
  vfs: get rid of old '->iterate' directory operation
  proc: fix missing conversion to 'iterate_shared'
  open: make RESOLVE_CACHED correctly test for O_TMPFILE

Now that we removed ->iterate we don't need to check for either
->iterate or ->iterate_shared in file_needs_f_pos_lock(). Simply check
for ->iterate_shared instead. This will tell us whether we need to
unconditionally take the lock. Not just does it allow us to avoid
checking f_inode's mode it also actually clearly shows that we're
locking because of readdir.
Signed-off-by: Christian Brauner <brauner@kernel.org>

All users now just use '->iterate_shared()', which only takes the
directory inode lock for reading.

Filesystems that never got convered to shared mode now instead use a
wrapper that drops the lock, re-takes it in write mode, calls the old
function, and then downgrades the lock back to read mode.

This way the VFS layer and other callers no longer need to care about
filesystems that never got converted to the modern era.

The filesystems that use the new wrapper are ceph, coda, exfat, jfs,
ntfs, ocfs2, overlayfs, and vboxsf.

Honestly, several of them look like they really could just iterate their
directories in shared mode and skip the wrapper entirely, but the point
of this change is to not change semantics or fix filesystems that
haven't been fixed in the last 7+ years, but to finally get rid of the
dual iterators.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

I'm looking at the directory handling due to the discussion about f_pos
locking (see commit 79796425: "file: reinstate f_pos locking
optimization for regular files"), and wanting to clean that up.

And one source of ugliness is how we were supposed to move filesystems
over to the '->iterate_shared()' function that only takes the inode lock
for reading many many years ago, but several filesystems still use the
bad old '->iterate()' that takes the inode lock for exclusive access.

See commit 61922694 ("introduce a parallel variant of ->iterate()")
that also added some documentation stating

      Old method is only used if the new one is absent; eventually it will
      be removed.  Switch while you still can; the old one won't stay.

and that was back in April 2016.  Here we are, many years later, and the
old version is still clearly sadly alive and well.

Now, some of those old style iterators are probably just because the
filesystem may end up having per-inode mutable data that it uses for
iterating a directory, but at least one case is just a mistake.

Al switched over most filesystems to use '->iterate_shared()' back when
it was introduced.  In particular, the /proc filesystem was converted as
one of the first ones in commit f50752ea ("switch all procfs
directories ->iterate_shared()").

But then later one new user of '->iterate()' was then re-introduced by
commit 6d9c939d ("procfs: add smack subdir to attrs").

And that's clearly not what we wanted, since that new case just uses the
same 'proc_pident_readdir()' and 'proc_pident_lookup()' helper functions
that other /proc pident directories use, and they are most definitely
safe to use with the inode lock held shared.

So just fix it.

This still leaves a fair number of oddball filesystems using the
old-style directory iterator (ceph, coda, exfat, jfs, ntfs, ocfs2,
overlayfs, and vboxsf), but at least we don't have any remaining in the
core filesystems.

I'm going to add a wrapper function that just drops the read-lock and
takes it as a write lock, so that we can clean up the core vfs layer and
make all the ugly 'this filesystem needs exclusive inode locking' be
just filesystem-internal warts.

I just didn't want to make that conversion when we still had a core user
left.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

O_TMPFILE is actually __O_TMPFILE|O_DIRECTORY. This means that the old
fast-path check for RESOLVE_CACHED would reject all users passing
O_DIRECTORY with -EAGAIN, when in fact the intended test was to check
for __O_TMPFILE.

Cc: stable@vger.kernel.org # v5.12+
Fixes: 99668f61 ("fs: expose LOOKUP_CACHED through openat2() RESOLVE_CACHED")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Message-Id: <20230806-resolve_cached-o_tmpfile-v1-1-7ba16308465e@cyphar.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Pull rust fixes from Miguel Ojeda:

 - Allocator: prevent mis-aligned allocation

 - Types: delete 'ForeignOwnable::borrow_mut'. A sound replacement is
   planned for the merge window

 - Build: fix bindgen error with UBSAN_BOUNDS_STRICT

* tag 'rust-fixes-6.5-rc5' of https://github.com/Rust-for-Linux/linux:
  rust: fix bindgen build error with UBSAN_BOUNDS_STRICT
  rust: delete `ForeignOwnable::borrow_mut`
  rust: allocator: Prevent mis-aligned allocation

Pull ata fix from Damien Le Moal:

 - Prevent the scsi disk driver from issuing a START STOP UNIT command
   for ATA devices during system resume as this causes various issues
   reported by multiple users.

* tag 'ata-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata,scsi: do not issue START STOP UNIT on resume

Pull smb client fix from Steve French:

 - Fix DFS interlink problem (different namespace)

* tag '6.5-rc4-smb3-client-fix' of git://git.samba.org/sfrench/cifs-2.6:
  smb: client: fix dfs link mount against w2k8

Pull powerpc fixes from Michael Ellerman:

 - Fix vmemmap altmap boundary check which could cause memory hotunplug
   failure

 - Create a dummy stackframe to fix ftrace stack unwind

 - Fix secondary thread bringup for Book3E ELFv2 kernels

 - Use early_ioremap/unmap() in via_calibrate_decr()

Thanks to Aneesh Kumar K.V, Benjamin Gray, Christophe Leroy, David
Hildenbrand, and Naveen N Rao.

* tag 'powerpc-6.5-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/powermac: Use early_* IO variants in via_calibrate_decr()
  powerpc/64e: Fix secondary thread bringup for ELFv2 kernels
  powerpc/ftrace: Create a dummy stackframe to fix stack unwind
  powerpc/mm/altmap: Fix altmap boundary check

Pull parisc architecture fixes from Helge Deller:

 - early fixmap preallocation to fix boot failures on kernel >= 6.4

 - remove DMA leftover code in parport_gsc

 - drop old comments and code style fixes

* tag 'parisc-for-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: unaligned: Add required spaces after ','
  parport: gsc: remove DMA leftover code
  parisc: pci-dma: remove unused and dead EISA code and comment
  parisc/mm: preallocate fixmap page tables at init

Pull clk fixes from Stephen Boyd:
 "A few clk driver fixes for some SoC clk drivers:

   - Change a usleep() to udelay() to avoid scheduling while atomic in
     the Amlogic PLL code

   - Revert a patch to the Mediatek MT8183 driver that caused an
     out-of-bounds write

   - Return the right error value when devm_of_iomap() fails in
     imx93_clocks_probe()

   - Constrain the Kconfig for the fixed mmio clk so that it depends on
     HAS_IOMEM and can't be compiled on architectures such as s390"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: fixed-mmio: make COMMON_CLK_FIXED_MMIO depend on HAS_IOMEM
  clk: imx93: Propagate correct error in imx93_clocks_probe()
  clk: mediatek: mt8183: Add back SSPM related clocks
  clk: meson: change usleep_range() to udelay() for atomic context

Merge tag 'hyperv-fixes-signed-20230804' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - Fix a bug in a python script for Hyper-V (Ani Sinha)

 - Workaround a bug in Hyper-V when IBT is enabled (Michael Kelley)

 - Fix an issue parsing MP table when Linux runs in VTL2 (Saurabh
   Sengar)

 - Several cleanup patches (Nischala Yelchuri, Kameron Carr, YueHaibing,
   ZhiHu)

* tag 'hyperv-fixes-signed-20230804' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Remove unused extern declaration vmbus_ontimer()
  x86/hyperv: add noop functions to x86_init mpparse functions
  vmbus_testing: fix wrong python syntax for integer value comparison
  x86/hyperv: fix a warning in mshyperv.h
  x86/hyperv: Disable IBT when hypercall page lacks ENDBR instruction
  x86/hyperv: Improve code for referencing hyperv_pcpu_input_arg
  Drivers: hv: Change hv_free_hyperv_page() to take void * argument

Pull RISC-V fixes from Palmer Dabbelt:

 - A pair of fixes for build-related failures in the selftests

 - A fix for a sparse warning in acpi_os_ioremap()

 - A fix to restore the kernel PA offset in vmcoreinfo, to fix crash
   handling

* tag 'riscv-for-linus-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  Documentation: kdump: Add va_kernel_pa_offset for RISCV64
  riscv: Export va_kernel_pa_offset in vmcoreinfo
  RISC-V: ACPI: Fix acpi_os_ioremap to return iomem address
  selftests: riscv: Fix compilation error with vstate_exec_nolibc.c
  selftests/riscv: fix potential build failure during the "emit_tests" step

Pull power management fix from Rafael Wysocki:
 "Fix a sparse warning triggered by the TPMI interface recently added to
  the Intel RAPL power capping driver (Zhang Rui)"

* tag 'pm-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  powercap: intel_rapl: Fix a sparse warning in TPMI interface

Commit 3bcbc209 ("selftests/rseq: Play nice with binaries statically
linked against glibc 2.35+") which is now in Linus' tree introduced uses
of __weak but did nothing to ensure that a definition is provided for it
resulting in build failures for the rseq tests:

rseq.c:41:1: error: unknown type name '__weak'
__weak ptrdiff_t __rseq_offset;
^
rseq.c:41:17: error: expected ';' after top level declarator
__weak ptrdiff_t __rseq_offset;
                ^
                ;
rseq.c:42:1: error: unknown type name '__weak'
__weak unsigned int __rseq_size;
^
rseq.c:43:1: error: unknown type name '__weak'
__weak unsigned int __rseq_flags;

Fix this by using the definition from tools/include compiler.h.

Fixes: 3bcbc209 ("selftests/rseq: Play nice with binaries statically linked against glibc 2.35+")
Signed-off-by: Mark Brown <broonie@kernel.org>
Message-Id: <20230804-kselftest-rseq-build-v1-1-015830b66aa9@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull arm64 fixes from Catalin Marinas:
 "More SVE/SME fixes for ptrace() and for the (potentially future) case
  where SME is implemented in hardware without SVE support"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64/fpsimd: Sync and zero pad FPSIMD state for streaming SVE
  arm64/fpsimd: Sync FPSIMD state with SVE for SME only systems
  arm64/ptrace: Don't enable SVE when setting streaming SVE
  arm64/ptrace: Flush FP state when setting ZT0
  arm64/fpsimd: Clear SME state in the target task when setting the VL

Pull mtd fixes from Miquel Raynal:
 "Raw NAND fixes:
   - fsl_upm: Fix an off-by one test in fun_exec_op()
   - Rockchip:
       - Align hwecc vs. raw page helper layouts
       - Fix oobfree offset and description
   - Meson: Fix OOB available bytes for ECC
   - Omap ELM: Fix incorrect type in assignment

  SPI-NOR fix:
   - Avoid holes in struct spi_mem_op

  Hyperbus fix:
   - Add Tudor as reviewer in MAINTAINERS

  SPI-NAND fixes:
   - Winbond and Toshiba: Fix ecc_get_status"

* tag 'mtd/fixes-for-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: rawnand: fsl_upm: Fix an off-by one test in fun_exec_op()
  mtd: spi-nor: avoid holes in struct spi_mem_op
  MAINTAINERS: Add myself as reviewer for HYPERBUS
  mtd: rawnand: rockchip: Align hwecc vs. raw page helper layouts
  mtd: rawnand: rockchip: fix oobfree offset and description
  mtd: rawnand: meson: fix OOB available bytes for ECC
  mtd: rawnand: omap_elm: Fix incorrect type in assignment
  mtd: spinand: winbond: Fix ecc_get_status
  mtd: spinand: toshiba: Fix ecc_get_status

Pull drm fixes from Dave Airlie:
 "Small set of fixes this week, i915 and a few misc ones. I didn't see
  an amd pull so maybe next week it'll have a few more on that driver.

  ttm:
   - NULL ptr deref fix

  panel:
   - add missing MODULE_DEVICE_TABLE

  imx/ipuv3:
   - timing fix

  i915:
   - Fix bug in getting msg length in AUX CH registers handler
   - Gen12 AUX invalidation fixes
   - Fix premature release of request's reusable memory"

* tag 'drm-fixes-2023-08-04' of git://anongit.freedesktop.org/drm/drm:
  drm/panel: samsung-s6d7aa0: Add MODULE_DEVICE_TABLE
  drm/i915: Fix premature release of request's reusable memory
  drm/i915/gt: Support aux invalidation on all engines
  drm/i915/gt: Poll aux invalidation register bit on invalidation
  drm/i915/gt: Enable the CCS_FLUSH bit in the pipe control and in the CS
  drm/i915/gt: Rename flags with bit_group_X according to the datasheet
  drm/i915/gt: Ensure memory quiesced before invalidation
  drm/i915: Add the gen12_needs_ccs_aux_inv helper
  drm/i915/gt: Cleanup aux invalidation registers
  drm/i915/gvt: Fix bug in getting msg length in AUX CH registers handler
  drm/imx/ipuv3: Fix front porch adjustment upon hactive aligning
  drm/ttm: check null pointer before accessing when swapping

Pull ceph fixes from Ilya Dryomov:
 "Two patches to improve RBD exclusive lock interaction with
  osd_request_timeout option and another fix to reduce the potential for
  erroneous blocklisting -- this time in CephFS. All going to stable"

* tag 'ceph-for-6.5-rc5' of https://github.com/ceph/ceph-client:
  libceph: fix potential hang in ceph_osdc_notify()
  rbd: prevent busy loop when requesting exclusive lock
  ceph: defer stopping mdsc delayed_work

In commit 20ea1e7d ("file: always lock position for
FMODE_ATOMIC_POS") we ended up always taking the file pos lock, because
pidfd_getfd() could get a reference to the file even when it didn't have
an elevated file count due to threading of other sharing cases.

But Mateusz Guzik reports that the extra locking is actually measurable,
so let's re-introduce the optimization, and only force the locking for
directory traversal.

Directories need the lock for correctness reasons, while regular files
only need it for "POSIX semantics".  Since pidfd_getfd() is about
debuggers etc special things that are _way_ outside of POSIX, we can
relax the rules for that case.
Reported-by: Mateusz Guzik <mjguzik@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/linux-fsdevel/20230803095311.ijpvhx3fyrbkasul@f/Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'kvmarm-fixes-6.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.5, part #2

 - Fixes for the configuration of SVE/SME traps when hVHE mode is in use

 - Allow use of pKVM on systems with FF-A implementations that are v1.0
   compatible

 - Request/release percpu IRQs (arch timer, vGIC maintenance) correctly
   when pKVM is in use

 - Fix function prototype after __kvm_host_psci_cpu_entry() rename

 - Skip to the next instruction when emulating writes to TCR_EL1 on
   AmpereOne systems

To avoid possible time-of-check/time-of-use issues, the GHCB should
almost never be accessed outside dump_ghcb, sev_es_sync_to_ghcb
and sev_es_sync_from_ghcb.  The only legitimate uses are to set the
exitinfo fields and to find the address of the scratch area embedded
in the ghcb.  Accessing ghcb_usage also goes through svm->sev_es.ghcb
in sev_es_validate_vmgexit(), but that is because anyway the value is
not used.

Removing a shortcut variable that contains the value of svm->sev_es.ghcb
makes these cases a bit more verbose, but it limits the chance of someone
reading the ghcb by mistake.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

A KVM guest using SEV-ES or SEV-SNP with multiple vCPUs can trigger
a double fetch race condition vulnerability and invoke the VMGEXIT
handler recursively.

sev_handle_vmgexit() maps the GHCB page using kvm_vcpu_map() and then
fetches the exit code using ghcb_get_sw_exit_code().  Soon after,
sev_es_validate_vmgexit() fetches the exit code again. Since the GHCB
page is shared with the guest, the guest is able to quickly swap the
values with another vCPU and hence bypass the validation. One vmexit code
that can be rejected by sev_es_validate_vmgexit() is SVM_EXIT_VMGEXIT;
if sev_handle_vmgexit() observes it in the second fetch, the call
to svm_invoke_exit_handler() will invoke sev_handle_vmgexit() again
recursively.

To avoid the race, always fetch the GHCB data from the places where
sev_es_sync_from_ghcb stores it.

Exploiting recursions on linux kernel has been proven feasible
in the past, but the impact is mitigated by stack guard pages
(CONFIG_VMAP_STACK).  Still, if an attacker manages to call the handler
multiple times, they can theoretically trigger a stack overflow and
cause a denial-of-service, or potentially guest-to-host escape in kernel
configurations without stack guard pages.

Note that winning the race reliably in every iteration is very tricky
due to the very tight window of the fetches; depending on the compiler
settings, they are often consecutive because of optimization and inlining.

Tested by booting an SEV-ES RHEL9 guest.

Fixes: CVE-2023-4155
Fixes: 291bd20d ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT")
Cc: stable@vger.kernel.org
Reported-by: Andy Nguyen <theflow@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Validation of the GHCB is susceptible to time-of-check/time-of-use vulnerabilities.
To avoid them, we would like to always snapshot the fields that are read in
sev_es_validate_vmgexit(), and not use the GHCB anymore after it returns.

This means:

- invoking sev_es_sync_from_ghcb() before any GHCB access, including before
  sev_es_validate_vmgexit()

- snapshotting all fields including the valid bitmap and the sw_scratch field,
  which are currently not caching anywhere.

The valid bitmap is the first thing to be copied out of the GHCB; then,
further accesses will use the copy in svm->sev_es.

Fixes: 291bd20d ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

We have a function sve_sync_from_fpsimd_zeropad() which is used by the
ptrace code to update the SVE state when the user writes to the the
FPSIMD register set.  Currently this checks that the task has SVE
enabled but this will miss updates for tasks which have streaming SVE
enabled if SVE has not been enabled for the thread, also do the
conversion if the task has streaming SVE enabled.

Fixes: e12310a0 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-ssve-no-sve-v1-3-49df214bfb3e@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Currently we guard FPSIMD/SVE state conversions with a check for the system
supporting SVE but SME only systems may need to sync streaming mode SVE
state so add a check for SME support too.  These functions are only used
by the ptrace code.

Fixes: e12310a0 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-ssve-no-sve-v1-2-49df214bfb3e@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Systems which implement SME without also implementing SVE are
architecturally valid but were not initially supported by the kernel,
unfortunately we missed one issue in the ptrace code.

The SVE register setting code is shared between SVE and streaming mode
SVE. When we set full SVE register state we currently enable TIF_SVE
unconditionally, in the case where streaming SVE is being configured on a
system that supports vanilla SVE this is not an issue since we always
initialise enough state for both vector lengths but on a system which only
support SME it will result in us attempting to restore the SVE vector
length after having set streaming SVE registers.

Fix this by making the enabling of SVE conditional on setting SVE vector
state. If we set streaming SVE state and SVE was not already enabled this
will result in a SVE access trap on next use of normal SVE, this will cause
us to flush our register state but this is fine since the only way to
trigger a SVE access trap would be to exit streaming mode which will cause
the in register state to be flushed anyway.

Fixes: e12310a0 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-ssve-no-sve-v1-1-49df214bfb3e@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>