Commit Graph

1444547 Commits

Author SHA1 Message Date
Michael S. Tsirkin
48dbe47321 KVM: guest_memfd: fix NUMA interleave index double-counting
kvm_gmem_get_policy() sets the interleave index (the output param that's
typically named "ilx") to the full page offset (vm_pgoff + vma offset).
But get_vma_policy() adds the page offset on top of the interleave index,
and so the offset is counted twice.  This causes NUMA interleaving to skip
nodes: for order-0 pages the effective index jumps by 2 for each
consecutive page.

The vm_op.get_policy() implementation should return only a per-file bias in
the interleave index (like shmem_get_policy does with inode->i_ino),
letting get_vma_policy() add the page-offset component.

Fix by setting the output interleave index to the inode number (a la shmem)
instead of the full page offset, as the index is intended to be a constant,
semi-random value for a given file, e.g. so that interleaving doesn't start
at the same node for every file, and so that allocations are round-robined
across nodes based on the page offset (the selected node would bounce/skip
around if the index isn't constant).

Found by Sashiko (sashiko.dev) AI code review.

Fixes: ed1ffa810b ("KVM: guest_memfd: Enforce NUMA mempolicy using shared policy")
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Shivank Garg <shivankg@amd.com>
Tested-by: Shivank Garg <shivankg@amd.com>
Fixes: 7f3779a3ac ("mm/filemap: Add NUMA mempolicy support to filemap_alloc_folio()")
Link: https://patch.msgid.link/0eff0a90667b900bee837d06b5db5025e1f304b5.1780501924.git.mst@redhat.com
[sean: use reverse fir-tree, massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-06-08 09:15:43 -07:00
Sean Christopherson
b408b52e71 KVM: selftests: Add guest_memfd regression test signed offset+size bug
Add a regression (and proof-of-bug) testcase to ensure KVM rejects an
offset+size that would result in a negative value when computed as a signed
64-bit value.  KVM had a flaw where it would allow binding a memslot to a
guest_memfd instance even with a wildly out-of-range offset, if the offset
and size were both positive values, but the combined offset+size was
negative.

Use "0x7fffffffffffffffull - page_size", i.e. "INT64_MAX - page_size", for
the offset as the size of the guest_memfd file must be at least page_size
(KVM requires memslots and gmem files to be host page-size aligned).  I.e.
"INT64_MAX - page_size + size" is guaranteed to generate an offset+size
that is negative when converted to a signed 64-bit value *and* honors KVM's
alignment requirements.

Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Tested-by: Ackerley Tng <ackerleytng@google.com>
Link: https://patch.msgid.link/20260602170921.1304394-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-06-03 05:39:24 -07:00
Sean Christopherson
b7a23fb0ed KVM: selftests: Expand the guest_memfd test macros to allow passing the VM
Expand the gmem test macros to allow passing the VM to testcases, without
needing to plumb the VM into _every_ testcase, as the vast majority of
testcases only need the fd and size.

No functional change intended.

Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Tested-by: Ackerley Tng <ackerleytng@google.com>
Link: https://patch.msgid.link/20260602170921.1304394-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-06-03 05:39:24 -07:00
Sean Christopherson
eba85fee7f KVM: guest_memfd: Treat memslot binding offset+size as unsigned values
When binding a memslot to a guest_memfd file, treat the offset and size as
unsigned values to fix a bug where the sum of the two can result in a false
negative when checking for overflow against the size of the file.  Passing
unsigned values also avoids relying on somewhat obscure checks in other
flows for safety, and tracks the offset and size as they are intended to be
tracked, as unsigned values.

On 64-bit kernels, the number of pages a memslot contains and thus the size
(and offset) of its guest_memfd binding are unsigned 64-bit values.  Taking
the offset+size as an loff_t instead of a uoff_t inadvertently converts
the unsigned value to a signed value if the offset and/or size is massive.

Locally storing the offset and size as signed values is benign in and of
itself (though even that is *extremely* difficult to discern), but
operating on their sum is not.

For the offset, KVM explicitly checks against a negative value, which might
seem like a bug as KVM could incorrectly reject a legitimate binding, but
that's not actually the case as KVM_CREATE_GUEST_MEMFD takes a signed value
for its size, i.e. a would-be-negative offset is also greater than the
maximum possible size of any guest_memfd file.

Regarding the size, while KVM lacks an explicit check for a negative value,
i.e. seemingly has a flawed overflow check, KVM restricts the number of
pages in a single memslot to the largest positive signed 32-bit value:

        if (id < KVM_USER_MEM_SLOTS &&
            (mem->memory_size >> PAGE_SHIFT) > KVM_MEM_MAX_NR_PAGES)
                return -EINVAL;

and so that maximum "size" will ever be is 0x7fffffff000.

The sum of the two is, however, problematic.  While the size is restricted
by KVM's memslot logic, the offset is not, i.e. the offset is completely
unchecked until the "offset + size > i_size_read(inode)" check.  If the
offset is the (nearly) largest possible _positive_ value, then adding size
to the offset can result in a signed, negative 64-bit value.  When compared
against the size of the file (guaranteed to be positive), the negative sum
is always smaller, and KVM incorrectly allows the absurd offset.

Opportunistically add missing includes in kvm_mm.h (instead of relying on
its parents).

Fixes: a7800aa80e ("KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory")
Cc: stable@vger.kernel.org
Cc: Ackerley Tng <ackerleytng@google.com>
Reviewed-by: Michael Roth <michael.roth@amd.com>
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Link: https://patch.msgid.link/20260602170921.1304394-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-06-03 05:39:24 -07:00
Sean Christopherson
b0e476eb75 KVM: selftests: Remove unnecessary "%s" formatting of a constant string
Drop superfluous %s formatting from assertions in the guest_memfd overlap
testcases, as the string being printed doesn't require runtime formatting.

No functional change intended.

Reported-by: Ackerley Tng <ackerleytng@google.com>
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Link: https://patch.msgid.link/20260522172151.3530267-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-05-26 12:23:36 -07:00
Zongyao Chen
772989854a KVM: selftests: Test guest_memfd binding overlap without GPA overlap
The guest_memfd binding overlap test recreates the deleted slot with GPA
ranges that overlap the still-live slot.  KVM rejects those attempts from
the generic memslot overlap check before reaching kvm_gmem_bind(), so the
test can pass even if guest_memfd binding overlap detection is broken.

Recreate the slot at its original, non-overlapping GPA and use guest_memfd
offsets that overlap the front and back halves of the other slot's binding.
Expand the guest_memfd so the back-half case remains within the file size.

Fixes: 2feabb855d ("KVM: selftests: Expand set_memory_region_test to validate guest_memfd()")
Signed-off-by: Zongyao Chen <ZongYao.Chen@linux.alibaba.com>
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Tested-by: Ackerley Tng <ackerleytng@google.com>
[sean: keep the existing GPA overlap testcases]
Link: https://patch.msgid.link/20260522172151.3530267-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-05-26 12:23:36 -07:00
Zongyao Chen
7ea987a905 KVM: guest_memfd: Return -EEXIST for overlapping bindings
KVM_SET_USER_MEMORY_REGION2 rejects guest_memfd ranges that overlap an
existing binding, but kvm_gmem_bind() currently reports the failure through
its generic -EINVAL path.  That makes binding conflicts indistinguishable
from malformed guest_memfd parameters.

Return -EEXIST when the target guest_memfd range is already bound, matching
the errno used for overlapping GPA memslots and making the two types of
range conflicts report the same class of error to userspace.

Note, returning -EINVAL was definitely not intentional, as guest_memfd
support was accompanied by a selftest to verify that attempting to create
overlapping bindings fails with -EEXIST.  Except the selftest was also
flawed in that it unintentionally overlapped memslot GPAs, and so failed
on KVM's common memslot checks before reaching guest_memfd.

Fixes: a7800aa80e ("KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory")
Signed-off-by: Zongyao Chen <ZongYao.Chen@linux.alibaba.com>
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Tested-by: Ackerley Tng <ackerleytng@google.com>
[sean: call out that the original intent was to return -EEXIST]
Link: https://patch.msgid.link/20260522172151.3530267-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-05-26 12:23:36 -07:00
Paolo Bonzini
b7fbe9a1bf Merge branch 'kvm-apx-prepare' into HEAD
Clean up KVM's register tracking and storage, primarily to prepare for
APX support, which expands the maximum number of GPRs from 16 to 32.
2026-05-13 12:38:31 -04:00
Sean Christopherson
39a5ee37be KVM: x86: Use a proper bitmap for tracking available/dirty registers
Define regs_{avail,dirty} as bitmaps instead of U32s to harden against
overflow, and to allow for dynamically sizing the bitmaps when APX comes
along, which will add 16 more GPRs (R16-R31) and thus increase the total
number of registers beyond 32.

Open code writes in the "reset" APIs, as the writes are hot paths and
bitmap_write() is complete overkill for what KVM needs.  Even better,
hardcoding writes to entry '0' in the array is a perfect excuse to assert
that the array contains exactly one entry, e.g. to effectively add guard
against defining R16-R31 in 32-bit kernels.

For all intents and purposes, no functional change intended even though
using bitmap_fill() will mean "undefined" registers are no longer marked
available and dirty (KVM should never be querying those bits).

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Message-ID: <20260409224236.2021562-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-13 12:38:06 -04:00
Sean Christopherson
133ecccbfe KVM: x86: Track available/dirty register masks as "unsigned long" values
Convert regs_{avail,dirty} and all related masks to "unsigned long" values
as an intermediate step towards declaring the fields as actual bitmaps, and
as a step toward support APX, which will push the total number of registers
beyond 32 on 64-bit kernels.

Opportunistically convert TDX's ULL bitmask to a UL to match everything
else (TDX is 64-bit only, so it's a nop in the end).

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Message-ID: <20260409224236.2021562-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-13 12:38:06 -04:00
Sean Christopherson
0af556e6f9 KVM: x86: Add wrapper APIs to reset dirty/available register masks
Add wrappers for setting regs_{avail,dirty} in anticipation of turning the
fields into proper bitmaps, at which point direct writes won't work so
well.

Deliberately leave the initialization in kvm_arch_vcpu_create() as-is,
because the regs_avail logic in particular is special in that it's the one
and only place where KVM marks eagerly synchronized registers as available.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Message-ID: <20260409224236.2021562-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-13 12:38:06 -04:00
Sean Christopherson
3b628ef168 KVM: nVMX: Do a bitwise-AND of regs_avail when switching active VMCS
When switching between vmcs01 and vmcs02, do a bitwise-AND of regs_avail
to effectively reset the mask for the new VMCS, purely to be consistent
with all other "full" writes of regs_avail.  In practice, a straight write
versus a bitwise-AND will yield the same result, as kvm_arch_vcpu_create()
marks *all* registers available (and dirty), and KVM never marks registers
unavailable unless they're lazily loaded.

This will allow adding wrapper APIs to set regs_{avail,dirty} without
having to add special handling for a nVMX use case that doesn't exist in
practice.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Message-ID: <20260409224236.2021562-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-13 12:38:06 -04:00
Sean Christopherson
e31de57910 KVM: x86: Drop the "EX" part of "EXREG" to avoid collision with APX
Now that NR_VCPU_REGS is no longer a thing, and now that now that RIP is
effectively an EXREG, drop the "EX" is for extended (or maybe extra?")
prefix from non-GPR registers to avoid a collision with APX (Advanced
Performance Extensions), which adds:

  16 additional general-purpose registers (GPRs) R16–R31, also referred
  to as Extended GPRs (EGPRs)  in this document;

I.e. KVM's version of "extended" won't match with APX's definition.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Message-ID: <20260409224236.2021562-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-13 12:38:06 -04:00
Sean Christopherson
3b4ec7dcdf KVM: x86: Add dedicated storage for guest RIP
Add kvm_vcpu_arch.rip to track guest RIP instead of including it in the
generic regs[] array.  Decoupling RIP from regs[] will allow using a
*completely* arbitrary index for RIP, as opposed to the mostly-arbitrary
index that is currently used.  That in turn will allow using indices
16-31 to track R16-R31 that are coming with APX.

Note, although RIP can used for addressing, it does NOT have an
architecturally defined index, and so can't be reached via flows like
get_vmx_mem_address() where KVM "blindly" reads a general purpose register
given the SIB information reported by hardware.  For RIP-relative
addressing, hardware reports the full "offset" in vmcs.EXIT_QUALIFICATION.

Note #2, keep the available/dirty tracking as RSP is context switched
through the VMCS, i.e. needs to be cached for VMX.

Opportunistically rename NR_VCPU_REGS to NR_VCPU_GENERAL_PURPOSE_REGS to
better capture what it tracks, and so that KVM can slot in R16-R13 without
running into weirdness where KVM's definition of "EXREG" doesn't line up
with APX's definition of "extended reg".

No functional change intended.

Cc: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Chang S. Bae <chang.seok.bae@intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Message-ID: <20260409224236.2021562-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-13 12:38:06 -04:00
Paolo Bonzini
fcaf986d10 Merge branch 'kvm-vmenter' into HEAD
Move SPEC_CTRL handling for VMX entirely to vmenter.S, also improving
assembly code reuse between SVM and VMX.

The prototype of __vmx_vcpu_run() and __svm_vcpu_run() becomes
the same, with a set of bit flags for the second argument.
The register allocation also becomes very similar, with %edi/%rdi
pointing to the vmx (resp. svm) argument.

Thanks to this, the code to save and restore SPEC_CTRL values for the
host and guest is the same up to the register names and can be dropped
into a new header arch/x86/kvm/vmenter.h.  APX enablement will also move
common code to load and save registers from VMX and SVM to vmenter.h.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 15:01:36 +02:00
Paolo Bonzini
2be108307e Merge branch 'kvm-mbec' into HEAD
This topic branch introduces support for two related features that
Hyper-V uses in its implementation of Virtual Secure Mode; these are
Intel Mode-Based Execute Control and AMD Guest Mode Execution Trap.

Both MBEC and GMET allow more granular control over execute permissions,
with different levels of separation between supervisor and user mode.
MBEC provides support for separate supervisor and user-mode bits in the
PTEs; GMET instead lacks supervisor-mode only execution (with NX=0,
"both" is represented by U=0 and user-mode only by U=1).  GMET was
clearly inspired by SMEP though with some differences and annoyances.

The implementation starts from two changes to core MMU code, both
of which help making the actual feature almost trivial to implement:

- first, I'm cleaning up the implementation of nVMX exec-only, by
  properly adding read permissions to the ACC_* constant and to the
  permission bitmask machinery.  Jon also had to add a fourth ACC_*
  bit, but used it only in the special case of nested MBEC; here
  instead ACC_READ_MASK is the normality, which simplifies testing
  a lot and removes gratuitous complexity.

- second, I'm enforcing that KVM runs with MBEC/GMET enabled even in
  non-nested mode, if it wants to provide the feature to nested
  hypervisors.  This makes the creation of SPTEs looks exactly the
  same for L1 and L2 guests, despite only the latter using MBEC/GMET
  fully; the difference lies only in the input access permissions.

This strategy adds a limited amount of complexity to the core is limited,
while providing for an almost entirely seamless support of nested
hypervisors.

Later patches have to use slightly different meanings for ACC_* in Intel
and AMD.  On the Intel side, some work is needed in order to split
shadow_x_mask and ACC_EXEC_MASK in two; now that there is an actual
ACC_READ_MASK to be used for exec-only pages, ACC_USER_MASK is unused
and can be reused as ACC_USER_EXEC_MASK.  However, unlike the older
ACC_USER_MASK hack these differences are backed by concrete concepts
of the page table format, and there is always a 1:1 mapping from ACC_*
bits to PT_*_MASK or shadow_*_mask:

                            Intel                 AMD
     --------------------   -------------------   -------------------
     ACC_READ_MASK          PT_PRESENT_MASK       PT_PRESENT_MASK
     ACC_WRITE_MASK         PT_WRITABLE_MASK      PT_WRITABLE_MASK
     ACC_EXEC_MASK          shadow_xs_mask        shadow_nx_mask
     ACC_USER_MASK          ---                   shadow_user_mask
     ACC_USER_EXEC_MASK     shadow_xu_mask        ---

On Intel, ACC_EXEC_MASK is used for kernel-mode execution and is tied to
shadow_xs_mask (when MBEC is disabled, ACC_USER_EXEC_MASK and the XU bit
are computed but ineffective).  update_permission_bitmask() precomputes
all the necessary conditions.  On the AMD side, the U bit maps to
ACC_USER_MASK but nNPT adjusts the permission bitmask to ignore it for
reads and writes when GMET is active.  Despite the smaller scale of the
changes compared to MBEC, there are some changes to make to use GMET
for L1 guests, because the page tables have to be created with U=0.
This means that the root page has role.access != ACC_ALL and its
permissions have to be propagated down.

Note that with MBEC the user/supervisor distinction depends on the U
bit of the page tables rather than the CPL.  Processors provide this
information to the hypervisor through the "advanced EPT violation
vmexit info" feature, which is a requirement for KVM to use MBEC,
and kvm-intel.ko passes it to the MMU in PFERR_USER_MASK (unlike
kvm-amd.ko which computes it from the CPL).  This needs a small change
to pass the effective XWU permissions of the page tables down to
translate_nested_gpa().

The former "smep_andnot_wp" bit of cpu_role.base, now named "cr4_smep",
is repurposed for nested TDP to indicate that MBEC/GMET is on.  The minor
pessimization for shadow page tables (toggling CR4.SMEP now always forces
building a separate version of the shadow page tables, even though that's
technically unnecessary if CR4.WP=1) is not really worth fretting about;
in practice, guests are not going to flip CR4.SMEP in a way that would
prevent efficient reuse of shadow page tables.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 15:01:06 +02:00
Paolo Bonzini
687ee95c1b KVM: nSVM: enable GMET for guests
All that needs to be done is moving the GMET bit from vmcb12 to vmcb02.
The only new thing is that __nested_copy_vmcb_control_to_cache now
ensures that ignored-if-unavailable bits are zero in svm->nested.ctl.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:08 +02:00
Paolo Bonzini
878fffd76c KVM: SVM: work around errata 1218
According to AMD, the hypervisor may not be able to determine whether a
fault was a GMET fault or an NX fault based on EXITINFO1, and software
"must read the relevant VMCB to determine whether a fault was a GMET
fault or an NX fault".  The APM further details that they meant the
CPL field.

KVM uses the page fault error code to distinguish the causes of a
nested page fault, so recalculate the PFERR_USER_MASK bit of the
vmexit information.  Only do it for fetches and only if GMET is in
use, because KVM does not differentiate based on PFERR_USER_MASK
for other nested NPT page faults.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:08 +02:00
Paolo Bonzini
fe080f58de KVM: SVM: enable GMET and set it in MMU role
Set the GMET bit in the nested control field.  This has effectively
no impact as long as NPT page tables are changed to have U=0.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:08 +02:00
Paolo Bonzini
3129c6b81c KVM: x86/mmu: add support for GMET to NPT page table walks
GMET allows page table entries to be created with U=0 in NPT.
However, when GMET=1 U=0 only affects execution, not reads or
writes.  Ignore user faults on non-fetch accesses for NPT GMET.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:08 +02:00
Paolo Bonzini
ec65797ce3 KVM: x86/mmu: hard code more bits in kvm_init_shadow_npt_mmu
The host CR0 does not really reflect onto the NPT format because
hCR0.PG=1 must be set and hCR0.WP is ignored.  Carve that in stone
by removing the cr0 argument from kvm_init_shadow_npt_mmu.

Pass in WP=1 as well; it does not matter for GMET disabled because
PFERR_USER_MASK is always set, but a cleared W bit in the nested page
tables cannot be overridden in supervisor mode when GMET is enabled,
either.  In fact, since CR0.WP=0 is the weird "extra accesses allowed"
mode, it is acutally easier think about it being always set.

Likewise, clear X86_CR4_SMAP to avoid that KVM erroneously faults on
supervisor accesses to an U=1 page.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:08 +02:00
Paolo Bonzini
7658b9343a KVM: SVM: add GMET bit definitions
GMET (Guest Mode Execute Trap) is an AMD virtualization feature,
essentially the nested paging version of SMEP.  Hyper-V uses it;
add it in preparation for making it available to hypervisors
running under KVM.

Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:07 +02:00
Paolo Bonzini
978598a230 KVM: x86/mmu: introduce cpu_role bit for availability of PFEC.I/D
While GMET looks a lot like SMEP, it has several annoying differences.
The main one is that the availability of the I/D bit in the page fault
error code still depends on the host CR4.SMEP and EFER.NXE bits.  If the
base.cr4_smep bit of the cpu_role is (ab)used to enable GMET, there needs
to be another place where the host CR4.SMEP is read from; just merge it
with EFER.NXE into a new cpu_role bit that tells paging_tmpl.h whether
to set the I/D bit at all.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:07 +02:00
Paolo Bonzini
4ae0a67231 KVM: x86/mmu: propagate access mask from root pages down
Until now, all SPTEs have had all kinds of access allowed; however,
for GMET to be enabled all the pages have to have ACC_USER_MASK
disabled.  By marking them as supervisor pages, the processor
allows execution from either user or supervisor mode (unlike
for normal paging, NPT ignores the U bit for reads and writes).
That will mean that the root page's role has ACC_USER_MASK
cleared and that has to be propagated down through the kvm_mmu_page
tree.

Do that, and pass the required access to the
kvm_mmu_spte_requested tracepoint since it's not ACC_ALL
anymore.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:07 +02:00
Jon Kohler
55a71224bd KVM: nVMX: allow MBEC with EVMCS
Extend EVMCS1_SUPPORTED_2NDEXEC to allow MBEC and EVMCS to coexist.
Presenting both EVMCS and MBEC simultaneously causes KVM to filter out
MBEC and not present it as a supported control to the guest, preventing
performance gains from MBEC when Windows HVCI is enabled.

The guest may choose not to use MBEC (e.g., if the admin does not enable
Windows HVCI / Memory Integrity), but if they use traditional nested
virt (Hyper-V, WSL2, etc.), having EVMCS exposed is important for
improving nested guest performance. IOW allowing MBEC and EVMCS to
coexist provides maximum optionality to Windows users without
overcomplicating VM administration.

Signed-off-by: Jon Kohler <jon@nutanix.com>
Message-ID: <20251223054806.1611168-8-jon@nutanix.com>
Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:07 +02:00
Jon Kohler
606ddbfb4c KVM: nVMX: advertise MBEC to nested guests
Advertise SECONDARY_EXEC_MODE_BASED_EPT_EXEC (MBEC) to userspace, which
allows userspace to expose and advertise the feature to the guest.

When MBEC is enabled by the guest, it is passed to the MMU via cr4_smep,
and to the processor by the merging of vmcs12->secondary_vm_exec_control
into the VMCS02's secondary VM execution controls.

Signed-off-by: Jon Kohler <jon@nutanix.com>
Message-ID: <20251223054806.1611168-9-jon@nutanix.com>
Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:07 +02:00
Paolo Bonzini
d220bcf026 KVM: x86/mmu: add support for MBEC to EPT page table walks
Extend the page walker to support moving bit 10 of the PTEs
into ACC_USER_EXEC_MASK and bit 6 of the exit qualification of
EPT violation VM exits.

Note that while mmu_has_mbec()/cr4_smep affect the interpretation of
ACC_USER_EXEC_MASK and add bit 10 as a "present bit" in guest EPT page
table entries, they do not affect how KVM operates on SPTEs.  That's
because the MMU uses explicit ACC_USER_EXEC_MASK/shadow_xu_mask even for
the non-nested EPT; the only difference is that ACC_USER_EXEC_MASK and
ACC_EXEC_MASK will always be set in tandem outside the nested scenario.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:07 +02:00
Paolo Bonzini
9c167cb3c1 KVM: nVMX: pass PFERR_USER_MASK to MMU on EPT violations
For EPT, PFERR_USER_MASK refers not to the CPL of the guest,
but to the AND of the U bits encountered while walking guest
page tables; this is consistent with how MBEC differentiates
between XS and XU.  This is available through the
"advanced vmexit information for EPT violations" feature.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:06 +02:00
Paolo Bonzini
a0efd8cb22 KVM: nVMX: pass advanced EPT violation vmexit info to guest
KVM will use advanced vmexit information for EPT violations to
virtualize MBEC.  Pass it to the guest since it is easy and allows
testing nested nested.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:06 +02:00
Paolo Bonzini
a6b7b6b205 KVM: VMX: enable use of MBEC
If available, set SECONDARY_EXEC_MODE_BASED_EPT_EXEC in the secondary
execution controls.

The changes are limited because the MMU is designed to create the same
sPTEs independent of the MBEC setting.  On hosts lacking support for
MBEC, and in nested guests which cannot enable it as of this commit,
the XU bit is ignored by the processor.

Note that, as of this patch, MBEC is not available to L1 hypervisors
for their guests.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:55:00 +02:00
Paolo Bonzini
f603854a1b KVM: x86/mmu: move cr4_smep to base role
Guest page tables can be reused independent of the value of CR4.SMEP
(at least if WP=1).  However, this is not true of EPT MBEC pages,
because presence of EPT entries is signaled by bits 0-2 when MBEC
is off, and bits 0-2 + bit 10 when MBEC is on.

In preparation for enabling MBEC, move cr4_smep to the base role.
This makes the smep_andnot_wp bit redundant, so remove it.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:52:57 +02:00
Paolo Bonzini
2e111d932d KVM: x86/mmu: split XS/XU bits for EPT
When EPT is in use, replace ACC_USER_MASK with ACC_USER_EXEC_MASK,
so that supervisor and user-mode execution can be controlled
independently (ACC_USER_MASK would not allow a setting similar to
XU=0 XS=1 W=1 R=1).

Replace shadow_x_mask with shadow_xs_mask/shadow_xu_mask, to allow setting
XS and XU bits separately in EPT entries.

In fact, ACC_USER_EXEC_MASK is already set through ACC_ALL in the
kvm_mmu_page roles and propagates to the XU bit of sPTEs even if
MBEC is not (yet) enabled in the execution controls.  This is fine,
because the XU bit is ignored by the processor, and even once KVM
supports MBEC this mode will remain for processors that lack the
feature.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:52:57 +02:00
Paolo Bonzini
b95b398d2e KVM: x86: make translate_nested_gpa vendor-specific
EPT and NPT have different rules for passing PFERR_USER_MASK to the
nested page table walk.  In particular, for final addresses EPT
uses the U bit of the guest (nGVA->nGPA) walk.

While at it, remove PFERR_USER_MASK from the VMX version of the
function, since it is actually ignored by the tables that
update_permission_bitmask() generates for EPT.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:52:57 +02:00
Paolo Bonzini
2c89d57754 KVM: x86/mmu: pass pte_access for final nGPA->GPA walk
The XS/XU bit for EPT are only applied to final accesses, and use the
U bit from the page walk itself.  This is available in the page walker
as pte_access & ACC_USER_MASK but not available to translate_nested_gpa,
so pass it down.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:52:57 +02:00
Paolo Bonzini
bd1c40114b KVM: x86/mmu: pass PFERR_GUEST_PAGE/FINAL_MASK to kvm_translate_gpa
The XS/XU bit for EPT are only applied to final accesses, and use the
U bit from the page walk itself.  While strictly speaking not necessary
(any value of PFERR_USER_MASK would be the same for page table accesses,
because they're reads and writes only), it is clearer and less hackish
to only apply MBEC to PFERR_GUEST_FINAL_MASK.  Allow kvm-intel.ko to
distinguish the two cases.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:52:57 +02:00
Paolo Bonzini
a8827c1961 KVM: x86/mmu: introduce ACC_READ_MASK
Read permissions so far were only needed for EPT, which does not need
ACC_USER_MASK.  Therefore, for EPT page tables ACC_USER_MASK was repurposed
as a read permission bit.

In order to implement nested MBEC, EPT will genuinely have four kinds of
accesses, and there will be no room for such hacks; bite the bullet at
last, enlarging ACC_ALL to four bits and permissions[] to 2^4 bits (u16).

The new code does not enforce that the XWR bits on non-execonly processors
have their R bit set, even when running nested: none of the shadow_*_mask
values have bit 0 set, and make_spte() genuinely relies on ACC_READ_MASK
being requested!  This works because, if execonly is not supported by the
processor, shadow EPT will generate an EPT misconfig vmexit if the XWR
bits represent a non-readable page, and therefore the pte_access argument
to make_spte() will also always have ACC_READ_MASK set.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:52:55 +02:00
Paolo Bonzini
949aa12e03 KVM: x86/mmu: separate more EPT/non-EPT permission_fault()
Move more of EPT handling entirely in the existing "if (!ept)"
conditional.  Use a new "rf" variable instead of uf for read permissions
for clarity.

Merge smepf and ff into a single variable because EPT's "SMEP" (actually
MBEC) is defined differently and does not need smepf.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10 14:52:29 +02:00
Linus Torvalds
6d35786de2 Three bug fixes for x86:
* Check that nEPT/nNPT is enabled in slow flush hypercalls.  If it is
   not, the hypercalls can be processed as usual even while running a
   nested guest.
 
 * Fix shadow paging use-after-free due to page tables changing outside
   execution of the guest.  A bug that is 16 years old and stems from an
   imprecision in the very first KVM series.
 
 * Scan IRR whenever PID.ON is true, even if PIR is empty, which avoids
   a somewhat rare WARN.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "Three bug fixes for x86:

   - Check that nEPT/nNPT is enabled in slow flush hypercalls. If it is
     not, the hypercalls can be processed as usual even while running a
     nested guest

   - Fix shadow paging use-after-free due to page tables changing
     outside execution of the guest. A bug that is 16 years old and
     stems from an imprecision in the very first KVM series

   - Scan IRR whenever PID.ON is true, even if PIR is empty, which
     avoids a somewhat rare WARN"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Fix shadow paging use-after-free due to unexpected GFN
  KVM: x86: Fix misleading variable names and add more comments for PIR=>IRR flow
  KVM: x86: Do IRR scan in __kvm_apic_update_irr even if PIR is empty
  KVM: x86: check for nEPT/nNPT in slow flush hypercalls
2026-05-03 15:25:47 -07:00
Linus Torvalds
7fd2df204f Linux 7.1-rc2 2026-05-03 14:21:25 -07:00
Sean Christopherson
0cb2af2ea6 KVM: x86: Fix shadow paging use-after-free due to unexpected GFN
The shadow MMU computes GFNs for direct shadow pages using sp->gfn plus
the SPTE index. This assumption breaks for shadow paging if the guest
page tables are modified between VM entries (similar to commit
aad885e774, "KVM: x86/mmu: Drop/zap existing present SPTE even
when creating an MMIO SPTE", 2026-03-27).  The flow is as follows:

- a PDE is installed for a 2MB mapping, and a page in that area is
  accessed.  KVM creates a kvm_mmu_page consisting of 512 4KB pages;
  the kvm_mmu_page is marked by FNAME(fetch) as direct-mapped because
  the guest's mapping is a huge page (and thus contiguous).

- the PDE mapping is changed from outside the guest.

- the guest accesses another page in the same 2MB area.  KVM installs
  a new leaf SPTE and rmap entry; the SPTE uses the "correct" GFN
  (i.e. based on the new mapping, as changed in the previous step) but
  that GFN is outside of the [sp->gfn, sp->gfn + 511] range; therefore
  the rmap entry cannot be found and removed when the kvm_mmu_page
  is zapped.

- the memslot that covers the first 2MB mapping is deleted, and the
  kvm_mmu_page for the now-invalid GPA is zapped.  However, rmap_remove()
  only looks at the [sp->gfn, sp->gfn + 511] range established in step 1,
  and fails to find the rmap entry that was recorded by step 3.

- any operation that causes an rmap walk for the same page accessed
  by step 3 then walks a stale rmap and dereferences a freed kvm_mmu_page.
  This includes dirty logging or MMU notifier invalidations (e.g., from
  MADV_DONTNEED).

The underlying issue is that KVM's walking of shadow PTEs assumes that
if a SPTE is present when KVM wants to install a non-leaf SPTE, then the
existing kvm_mmu_page must be for the correct gfn.  Because the only way
for the gfn to be wrong is if KVM messed up and failed to zap a SPTE...
which shouldn't happen, but *actually* only happens in response to a
guest write.

That bug dates back literally forever, as even the first version of KVM
assumes that the GFN matches and walks into the "wrong" shadow page.
However, that was only an imprecision until 2032a93d66 ("KVM: MMU:
Don't allocate gfns page for direct mmu pages") came along.

Fix it by checking for a target gfn mismatch and zapping the existing
SPTE.  That way the old SP and rmap entries are gone, KVM installs
the rmap in the right location, and everyone is happy.

Fixes: 2032a93d66 ("KVM: MMU: Don't allocate gfns page for direct mmu pages")
Fixes: 6aa8b732ca ("kvm: userspace interface")
Reported-by: Alexander Bulekov <bkov@amazon.com>
Reported-by: Fred Griffoul <fgriffo@amazon.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://patch.msgid.link/20260503201029.106481-1-pbonzini@redhat.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-03 22:32:53 +02:00
Sean Christopherson
0aec99f9bf KVM: x86: Fix misleading variable names and add more comments for PIR=>IRR flow
Rename kvm_apic_update_irr()'s "irr_updated" and vmx_sync_pir_to_irr()'s
"got_posted_interrupt" to a more accurate "max_irr_is_from_pir", as neither
"irr_updated" nor "got_posted_interrupt" is accurate.
__kvm_apic_update_irr() and thus kvm_apic_update_irr() specifically return
true if and only if the highest priority IRQ, i.e. max_irr, is a "new"
pending IRQ from the PIR.  I.e. it's possible for the IRR to be updated,
i.e. for a posted IRQ to be "got", *without* the APIs returning true.

Expand vmx_sync_pir_to_irr()'s comment to explain why it's necessary to
set KVM_REQ_EVENT only if a "new" IRQ was found, and to explain why it's
safe to do so only if a new IRQ is also the highest priority pending IRQ.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://patch.msgid.link/20260503201703.108231-3-pbonzini@redhat.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-03 22:32:41 +02:00
Paolo Bonzini
33fd0ccd25 KVM: x86: Do IRR scan in __kvm_apic_update_irr even if PIR is empty
Fall back to apic_find_highest_vector() when PID.ON is set but PIR
turns out to be empty, to correctly report the highest pending interrupt
from the existing IRR.

In a nested VM stress test, the following WARNING fires in
vmx_check_nested_events() when kvm_cpu_has_interrupt() reports a pending
interrupt but the subsequent kvm_apic_has_interrupt() (which invokes
vmx_sync_pir_to_irr() again) returns -1:

  WARNING: CPU: 99 PID: 57767 at arch/x86/kvm/vmx/nested.c:4449 vmx_check_nested_events+0x6bf/0x6e0 [kvm_intel]
  Call Trace:
   kvm_check_and_inject_events
   vcpu_enter_guest.constprop.0
   vcpu_run
   kvm_arch_vcpu_ioctl_run
   kvm_vcpu_ioctl
   __x64_sys_ioctl
   do_syscall_64
   entry_SYSCALL_64_after_hwframe

The root cause is a race between vmx_sync_pir_to_irr() on the target vCPU
and __vmx_deliver_posted_interrupt() on a sender vCPU.  The sender
performs two individually-atomic operations that are not a single
transaction:

  1. pi_test_and_set_pir(vector)  -- sets the PIR bit
  2. pi_test_and_set_on()         -- sets PID.ON

The following interleaving triggers the bug:

  Sender vCPU (IPI):              Target vCPU (1st sync_pir_to_irr):
  B1: set PIR[vector]
                                  A1: pi_clear_on()
                                  A2: pi_harvest_pir() -> sees B1 bit
                                  A3: xchg() -> consumes bit, PIR=0
                                      (1st sync returns correct max_irr)
  B2: set PID.ON = 1

                                  Target vCPU (2nd sync_pir_to_irr):
                                  C1: pi_test_on() -> TRUE (from B2)
                                  C2: pi_clear_on() -> ON=0
                                  C3: pi_harvest_pir() -> PIR empty
                                  C4: *max_irr = -1, early return
                                      IRR NOT SCANNED

The interrupt is not lost (it resides in the IRR from the first sync and
is recovered on the next vcpu_enter_guest() iteration), but the incorrect
max_irr causes a spurious WARNING and a wasted L2 VM-Enter/VM-Exit cycle.

Fixes: b41f8638b9 ("KVM: VMX: Isolate pure loads from atomic XCHG when processing PIR")
Reported-by: Farrah Chen <farrah.chen@intel.com>
Analyzed-by: Chenyi Qiang <chenyi.qiang@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/kvm/20260428070349.1633238-1-chenyi.qiang@intel.com/T/
Link: https://patch.msgid.link/20260503201703.108231-2-pbonzini@redhat.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-03 22:18:15 +02:00
Paolo Bonzini
464af6fc2b KVM: x86: check for nEPT/nNPT in slow flush hypercalls
Checking is_guest_mode(vcpu) is incorrect, because translate_nested_gpa()
is only valid if an L2 guest is running *with nested EPT/NPT enabled*.
Instead use the same condition as translate_nested_gpa() itself.

Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <seanjc@google.com>
Fixes: aee738236d ("KVM: x86: Prepare kvm_hv_flush_tlb() to handle L2's GPAs", 2022-11-18)
Link: https://patch.msgid.link/20260503200905.106077-1-pbonzini@redhat.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-03 22:17:30 +02:00
Linus Torvalds
f377d0025e sh fixes for v7.1
- sh: Fix fallout from ZERO_PAGE consolidation
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Merge tag 'sh-for-v7.1-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux

Pull sh fix from John Paul Adrian Glaubitz:
 "The ZERO_PAGE consolidation in v7.1, introduced a regression on sh
  which made these systems unbootable.

  The problem was that on sh, the initial boot parameters were
  previously referenced as an array and after 6215d9f447 ("arch, mm:
  consolidate empty_zero_page"), they were referenced as a pointer which
  caused wrong code generation and boot hang.

  This changes the declaration back to being an array which fixes the
  boot hang"

* tag 'sh-for-v7.1-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux:
  sh: Fix fallout from ZERO_PAGE consolidation
2026-05-03 08:58:42 -07:00
Linus Torvalds
811129272d slab fixes for 7.1-rc1
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Merge tag 'slab-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab fixes from Vlastimil Babka:

 - Stable fixes for CONFIG_SMP=n where _nolock() allocations in NMI both
   at kmalloc and page allocator levels are not properly protected by
   the spin_trylock() semantics on !SMP (Harry Yoo)

* tag 'slab-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/slab: return NULL early from kmalloc_nolock() in NMI on UP
  mm/page_alloc: return NULL early from alloc_frozen_pages_nolock() in NMI on UP
2026-05-03 08:19:57 -07:00
Linus Torvalds
cffcf520fd Fix lockup in requeue-PI during signal/timeout wakeups,
by Sebastian Andrzej Siewior.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-urgent-2026-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fix from Ingo Molnar:
 "Fix lockup in requeue-PI during signal/timeout wakeups, by Sebastian
  Andrzej Siewior"

* tag 'locking-urgent-2026-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Prevent lockup in requeue-PI during signal/ timeout wakeup
2026-05-03 08:17:09 -07:00
Linus Torvalds
c3cba36b39 Miscellaneous scheduler fixes:
- Fix the delayed dequeue negative lag increase fix in the
    fair scheduler (Peter Zijlstra)
 
  - Fix wakeup_preempt_fair() to do proper delayed dequeue
    (Vincent Guittot)
 
  - Clear sched_entity::rel_deadline when initializing
    forked entities, which bug can cause all tasks to be
    EEVDF-ineligible, causing a NULL pointer dereference
    crash in pick_next_entity() (Zicheng Qu)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-urgent-2026-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:

 - Fix the delayed dequeue negative lag increase fix in the
   fair scheduler (Peter Zijlstra)

 - Fix wakeup_preempt_fair() to do proper delayed dequeue
   (Vincent Guittot)

 - Clear sched_entity::rel_deadline when initializing
   forked entities, which bug can cause all tasks to be
   EEVDF-ineligible, causing a NULL pointer dereference
   crash in pick_next_entity() (Zicheng Qu)

* tag 'sched-urgent-2026-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Clear rel_deadline when initializing forked entities
  sched/fair: Fix wakeup_preempt_fair() vs delayed dequeue
  sched/fair: Fix the negative lag increase fix
2026-05-03 08:05:23 -07:00
Mike Rapoport (Microsoft)
b0aa5e4b08 sh: Fix fallout from ZERO_PAGE consolidation
Consolidation of empty_zero_page declarations broke boot on sh.

sh stores its initial boot parameters in a page reserved in
arch/sh/kernel/head_32.S. Before commit 6215d9f447 ("arch, mm:
consolidate empty_zero_page") this page was referenced in C code
as an array and after that commit it is referenced as a pointer.

This causes wrong code generation and boot hang.

Declare boot_params_page as an array to fix the issue.

Reported-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Tested-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Fixes: 6215d9f447 ("arch, mm: consolidate empty_zero_page")
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
2026-05-03 16:35:40 +02:00
Linus Torvalds
66edb901bf This push contains the following changes:
- Reject algorithms with authsizes that are too short in authencesn.
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Merge tag 'v7.1-p3' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Pull crypto fix from Herbert Xu:

 - Reject algorithms with authsizes that are too short in authencesn

* tag 'v7.1-p3' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: authencesn - reject short ahash digests during instance creation
2026-05-02 12:31:43 -07:00
Linus Torvalds
4c2ed2a3db Description for this pull request:
- Fix a NULL pointer dereference in ntfs_index_walk_down() by validating
    index block allocation.
  - Fix a memory leak of the symlink target string in
    ntfs_reparse_set_wsl_symlink() during error paths.
  - Prevent VCN overflow and validate lowest_vcn in
    ntfs_mapping_pairs_decompress() to avoid runlist corruption.
  - Fix a page reference leak in ntfs_write_iomap_end_resident() when
    attribute search context allocation fails.
  - Fix an invalid PTR_ERR() usage on a valid folio pointer in
    __ntfs_bitmap_set_bits_in_run().
  - Correct directory link counting by dropping nlink only when the MFT
    record link count reaches zero for WIN32/DOS aliases.
  - Fix an uninitialized variable usage in ntfs_mapping_pairs_decompress()
    by returning an error pointer directly.
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Merge tag 'ntfs-for-7.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/ntfs

Pull ntfs fixes from Namjae Jeon:

 - Fix a NULL pointer dereference in ntfs_index_walk_down() by
   validating index block allocation

 - Fix a memory leak of the symlink target string in
   ntfs_reparse_set_wsl_symlink() during error paths

 - Prevent VCN overflow and validate lowest_vcn in
   ntfs_mapping_pairs_decompress() to avoid runlist corruption

 - Fix a page reference leak in ntfs_write_iomap_end_resident()
   when attribute search context allocation fails

 - Fix an invalid PTR_ERR() usage on a valid folio pointer in
   __ntfs_bitmap_set_bits_in_run()

 - Correct directory link counting by dropping nlink only when
   the MFT record link count reaches zero for WIN32/DOS aliases

 - Fix an uninitialized variable in ntfs_mapping_pairs_decompress()
   by returning an error pointer directly

* tag 'ntfs-for-7.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/ntfs:
  ntfs: Use return instead of goto in ntfs_mapping_pairs_decompress()
  ntfs: drop nlink once for WIN32/DOS aliases
  ntfs: fix invalid PTR_ERR() usage in __ntfs_bitmap_set_bits_in_run()
  ntfs: fix error handling in ntfs_write_iomap_end_resident()
  ntfs: fix VCN overflow in ntfs_mapping_pairs_decompress()
  ntfs: fix WSL symlink target leak on reparse failure
  ntfs: fix NULL dereference in ntfs_index_walk_down()
2026-05-02 12:25:57 -07:00