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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
- Don't apply va_align to hugetlb mappings on AMD F15h systems
that have custom va_align.bits values (Laurent Wandrebeck)
- Fix PMD teardown handling regression flagged by lockdep
(Mikhail Gavrilov)
- Hide ptrace header register offset macros behind __ASSEMBLER__ or
__FRAME_OFFSETS, to fix user-space build errors that may trigger
if they happen to shadow these short and generic macro names
(Nick Desaulniers)
* tag 'x86-urgent-2026-10-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
{x86,um}/uapi/ptrace: Guard register offset macros with __ASSEMBLER__ or __FRAME_OFFSETS
x86/mm: Drop unnecessary PMD page copy when freeing
x86/mm: Don't apply va_align to hugetlb mappings on AMD F15h
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Pull bpf fixes from Alexei Starovoitov:
- Fix overflow of backward jump offset in constant blinding
(Alexei Starovoitov)
- Fix packet range of packet pointers sharing an id when var_off
tightens umax of one pointer and not the other (Alexei Starovoitov)
- Fix objects stuck in free_by_rcu_ttrace list of bpf memalloc
(Alexei Starovoitov)
- Fix use-after-free of progs detached from busy trampolines: wait for
an RCU tasks grace period before freeing trampoline progs, and patch
detached progs out of trampoline images that are still in use
(Florent Revest)
- Hold map BTF for the memory allocator destructor record to fix UAF in
deferred bpf_mem_alloc destruction (Kumar Kartikeya Dwivedi)
- Fix missing migration protection in resizable hashtab
lookup_and_delete batch operation (Ömer Mete Kaya)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch()
selftests/bpf: Add a test for objects stuck in free_by_rcu_ttrace
bpf: Fix objects stuck in free_by_rcu_ttrace
bpf: Factor out __do_call_rcu_ttrace()
selftests/bpf: Test packet range of pointers sharing an id
bpf: Fix packet range of pointers sharing an id
selftests/bpf: Detach a trampoline prog while a task sleeps before it
bpf: Skip detached progs in trampoline images that are still in use
bpf: Wait for an RCU tasks grace period before freeing trampoline progs
bpf: Hold map BTF for the memory allocator destructor record
bpf: Fix overflow of jump offset in constant blinding
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git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull io_uring fixes from Jens Axboe:
- Fix a task_work add use-after-free with SQPOLL.
The sqpoll thread could pop and complete the last request while
io_req_normal_work_add() was still looking at them after the mpscq
push.
Use the same approach as DEFER_TASKRUN to protect from that, holding
an RCU read lock across the add, and have exit wait for an RCU grace
period for SQPOLL rings as well.
- CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
rings
- Mark the source filter table as COW when cloning bpf filters, so
registering another filter on the source doesn't modify the shared
table in place
- Initialize the task context before running the BPF loop
- Requeue zcrx multishot receives stopped by a local resource
- End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)
* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring: fix task_work add use-after-free with SQPOLL
io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
io_uring/zcrx: requeue multishot receives stopped by a local resource
io_uring: initialize task context before running the BPF loop
io_uring: zero big_cqe for aux CQEs on CQE32 rings
io_uring: fix free entry check for 32b CQEs on CQE32 rings
io_uring: only post the dummy skip CQE on CQE_MIXED rings
io_uring/bpf_filter: mark source as COW when cloning filters
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Add tests where two packet pointers share an id and tightening one
pointer's umax from its var_off would put it less than their constant
distance from the other's umax: with an index & 0x38 capped at 50, the
base pointer keeps umax 50, so the pointer 8 bytes further on must keep
umax 58, even though its known bits allow at most 56.
These refused a valid program or accepted an out-of-bounds access before
the fix:
- check the advanced copy, load through the base: valid, was refused;
- check the base, load the byte at base + 1 through a copy advanced by
8: was accepted;
- check base + 4, load 4 bytes at base + 2 through base + 8: reads two
bytes past the checked range, was accepted;
- the same as the second with data_meta pointers checked against data:
was accepted.
These pass with and without the fix and cover nearby paths:
- subtract an unknown scalar from a checked pointer and load below it
(the range is kept across a new id);
- reach a load through two paths whose checks cover 8 and 7 bytes after
the loaded pointer; the second path must not be pruned by the first;
- spill a copy of a pointer, check the pointer, fill the copy and load
one byte past the checked range: the load is refused, and the copy
has the range of the check.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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__FRAME_OFFSETS
The register offset macros in <asm/ptrace-abi.h> are guarded by
`defined(__ASSEMBLER__) || defined(__FRAME_OFFSETS)` for 64-bit, but
were left unguarded for 32-bit. This causes havoc for userspace that
happens to use identifiers colliding with these short macro names
(e.g., EBX, ECX, EAX, DS, ES, FS, GS, CS, SS). Without this guard,
userspace is forced to be super extra careful with include ordering to
minimize the chance of collision.
Wrap both the 32-bit and 64-bit register definitions under
`#if defined(__ASSEMBLER__) || defined(__FRAME_OFFSETS)`, and ensure
User-Mode Linux (UML) defines `__FRAME_OFFSETS` for 32-bit as well.
Closes: https://github.com/llvm/llvm-project/issues/217413
Assisted-by: LLM
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Tested-by: Elliott Hughes <enh@google.com>
Link: https://patch.msgid.link/20260821-ptrace_uapi-v1-1-3de8638a29f2@google.com
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On a box with a discrete GPU, lockdep reports a possible deadlock as
soon as kswapd shrinks the TTM page pool. The immediate cause is an
x86 commit that added an mmap_read_lock() to kernel page protection
munging code.
The huge vmap code holds the same lock over a GFP_KERNEL allocation,
which is a no-no now that reclaim can take it. That allocation is in a
page table *free* path and ends up being for dubious purposes[1].
Basically, it tries to avoid hardware setting Accessed=1 in page table
entries that are unreachable by the hardware, a non-issue.
Remove the PMD copy. Detach the original PMD page at the PUD, flush
the mid-level caches, and free the PTE tables straight from the
detached PMD page. With no allocation left, the locking issue is gone.
Lockdep splat/analysis:
WARNING: possible circular locking dependency detected
7.3.0-rc3-f6e7b42bf05b+ #183 Tainted: G U
------------------------------------------------------
kswapd0/269 is trying to acquire lock:
((init_mm).mmap_lock){++++}-{4:4}, at: change_page_attr_set_clr+0x29a/0x4a0
but task is already holding lock:
(pool_shrink_rwsem){.+.+}-{4:4}, at: ttm_pool_shrink+0xb2/0x330 [ttm]
Chain exists of:
(init_mm).mmap_lock --> fs_reclaim --> pool_shrink_rwsem
The cycle is built from three edges:
1) pool_shrink_rwsem -> (init_mm).mmap_lock
The TTM shrinker restores the caching attribute of every page it
frees, while holding pool_shrink_rwsem:
ttm_pool_shrink()
-> ttm_pool_dispose_list()
-> ttm_pool_free_page()
-> set_pages_wb()
-> change_page_attr_set_clr() [ init_mm mmap read lock ]
2) fs_reclaim -> pool_shrink_rwsem
The same shrinker, called from reclaim.
3) (init_mm).mmap_lock -> fs_reclaim
ioremap() installing a huge PUD mapping over an existing PMD table:
ioremap_page_range()
-> vmap_range_noflush()
-> vmap_try_huge_pud() [ init_mm mmap read lock ]
-> pud_free_pmd_page()
-> __get_free_page(GFP_KERNEL) [ enters reclaim ]
[ dhansen: Lots of changelog munging/trimming and merged comments from my
version of the fix. ]
Fixes: d5d8b8662e6e ("x86/mm/pat: Acquire init_mm read lock on attribute changes to avoid UAF")
Suggested-by: Pedro Falcato <pfalcato@suse.de>
Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Link: https://lore.kernel.org/20260916062222.27347-1-mikhail.v.gavrilov@gmail.com
Link: https://lore.kernel.org/all/e11449f0-d9ad-4d1b-ab21-2be7d71fe335@intel.com/ [1]
Link: https://patch.msgid.link/20260923223116.20090-1-mikhail.v.gavrilov@gmail.com
Cc: stable@vger.kernel.org
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get_align_mask() returns huge_page_mask_align() for hugetlbfs, but get_align_bits()
adds va_align.bits regardless, so vm_unmapped_area() returns an address off the huge
page boundary and __unmap_hugepage_range() hits BUG_ON(start & ~huge_page_mask(h)) at
teardown.
This can be triggered on Carrizo and FX-8370E, both hstates.
Pass the file to get_align_bits() and skip the randomisation for hugetlbfs.
[ bp: Massage commit message. ]
Fixes: 1317a5e7f7b1 ("arch/x86: teach arch_get_unmapped_area_vmflags to handle hugetlb mappings")
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Laurent Wandrebeck <l.wandrebeck@quelquesmots.fr>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org # 6.13+
Link: https://patch.msgid.link/20260922085032.46144-1-l.wandrebeck@quelquesmots.fr
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
- Fix preemption bugs in the SVSM vTPM guest implementation
(Melody Wang)
- Fix MCE-triggered hardware debug register corruption on
task migration (Masami Hiramatsu)
* tag 'x86-urgent-2026-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Fix hardware debug register corruption on task migration
x86/sev: Make vTPM SVSM calls preemption-safe
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events fixes from Ingo Molnar:
- Fixes for KVM guest PEBS virtualization (Sean Christopherson)
- Fixes for various Intel PMUs related to PEBS data-source (Dapeng Mi)
- Fix Intel Panther Cove event scheduling constraints (Dapeng Mi)
- Fix Intel DMR/NVL OMR extra registers event scheduling (Dapeng Mi)
- Rename two confusingly named PMU attributes (Dapeng Mi)
- Fix a refcount leak in attach_perf_ctx_data() (Namhyung Kim)
- Fix NULL pointer dereference crash in __perf_pmu_sched_task()
(Puranjay Mohan)
- Fix CPU-wide event scheduling (Puranjay Mohan)
- Fix x86 LBR branch entry generation (Puranjay Mohan)
* tag 'perf-urgent-2026-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fill branch entries with a single assignment
perf/core: Run sched_task() for PMUs with only CPU-wide events
perf/core: Fix NULL pmu_ctx passed to pmu->sched_task()
perf/core: Fix a refcount leak in attach_perf_ctx_data()
perf/x86/intel: Rename NVL offcore_rsp attribute to offmodule_rsp
perf/x86/intel: Rename DMR offcore_rsp attribute to offmodule_rsp
perf/x86/intel: Fix precise OMR event scheduling for DMR/NVL
perf/x86/intel: Constrain Panther Cove UOPS_DISPATCHED events to PMCs 0-3
perf/x86/intel: Delete dead NVL PEBS data-source initcall
perf/x86/intel: Fix Panther Cove PEBS data-source snoop states
perf/x86/intel: Remove incorrect Panther Cove PEBS data-source constraints
perf/x86/intel: Remove incorrect LionCove PEBS data-source constraints
perf/x86/intel: Update arw_latency_data() mem-op direction handling
perf/x86/intel: Fix DKT PEBS load/store direction for latency events, to fix sample classification
perf/x86/intel: Fix CMT PEBS load/store direction for latency events, to fix sample classification
perf/x86/intel: Fix GRT PEBS load/store direction for latency events, to fix sample classification
perf/x86/intel: Make @data a mandatory param for intel_guest_get_msrs()
perf/x86/intel: Don't pointlessly context switch DS_AREA (and PEBS config) if PEBS is unused
perf/x86/intel: Don't write PEBS_ENABLED on host<=>guest xfers if CPU has PEBS isolation, to fix stuck PEBS_ENABLED
perf/x86/intel: Ensure KVM guest PEBS path doesn't set unwanted PERF_GLOBAL_CTRL bits
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git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
Pull PCI fixes from Bjorn Helgaas:
- Make BAR resize work even for devices where no upstream bridge is
visible to the OS, which fixes an amdgpu regression on SolidRun
HoneyComb, which doesn't expose Root Ports to the OS (Liz Fong-Jones)
- Omit bus properties in dynamic OF nodes when a bridge has no
subordinate bus, which fixes early boot hangs caused by NULL pointer
dereferences with CONFIG_PCI_DYNAMIC_OF_NODES enabled (Angel J)
- Disable enhanced atomics on AMD NBIO 7.7 and 7.11 to avoid silent
data corruption on 64-bit DMAs (Mario Limonciello)
* tag 'pci-v7.3-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
x86/PCI: Disable enhanced atomics on AMD NBIO 7.7 and 7.11
PCI: of_property: Omit bus properties without a subordinate bus
PCI: Fix BAR resize for devices on a root bus
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Pull kvm fixes from Paolo Bonzini:
"Arm:
- Invalidate the ITS translation cache when the guest changes the
base address of the ITS tables (Fuad Tabba)
- Skip saving ITS devices with device IDs that are out-of-bounds
rather than failing the entire ITS save ioctl (Fuad Tabba)
- Close race between VM teardown and invalidations of nested MMUs
when handling MMU operations that are allowed to block (Lorenzo
Stoakes)
- Various fixes for the handling of the host's untrusted SVE
configuration in pKVM (Fuad Tabba)
- Make sure that empty SMCCC ranges based at 0 are rejected by the
kvm_smccc_set_filter() (Karl Mehltretter)
- Revoke the host mapping for pKVM's private stack pages, along with
a new sanity check that all mappings in the hyp's private VA range
have been correctly marked as hyp-owned (Fuad Tabba)
- Lifetime fixes for the array of shadow stage-2 MMUs, ensuring that
concurrent vCPU initialization cannot relocate in-use MMUs. Defer
the freeing of shadow stage-2 MMUs to the point that no other users
(e.g. MMU notifier) could reference them (Marc Zyngier)
- Drop useless WARN when rejecting an unsupported ioctl for pKVM
(Fuad Tabba)
- Fix the steal_time selftest to install correctly-sized mappings for
non-4K hosts (Sebastian Ott)
- Correct mapping of fine-grained trap for GCSPOPX instruction (Mark
Brown)
- Fix KVM_BUG_ON() due to missing handling of DBGBXVR<n> from 32-bit
guests (Karl Mehltretter)
RISC-V:
- Synchronize hrtimer during VCPU teardown
- Fix the conversion between vsip and hvip values
- Serialize IMSIC attributes with vCPU migration
- Release unused page after MMU invalidation
- Propagate interrupted G-stage faults to KVM user-space as EINTR
- Fix nested acceleration hfence entry update order
- Fix sdata leak and stale snapshot_addr in snapshot_set_shmem
- Preserve firmware counter value across PMU counter stop/start
- Report PMU snapshot write failure to the guest
- Fix perf-backed counter accounting across PMU stop and read
- Correctly propagate error of a hart status SBI call
s390:
- Ensure that accesses through kvm_arch_set_irq_inatomic mark as
dirty the pages that contain indicator and summary bits
- Fix compile warning for kvm_s390_update_cmma_dirty()
- Fix incorrect propagation of ENOENT from _gaccess_shadow_fault() to
userspace
- Move s390_kvm_mmu_commit_memory_region() into
s390_kvm_mmu_prepare_memory_region() so that it can fail instead of
WARN
- Add missing srcu in kvm_s390_set_irq_state()
- Fix potential races in storage functions
- Fix race in _destroy_pages_crste()
- Fix issues in the handling of KVM interrupt and page resources,
when a queue that is assigned to a mediated device (mdev) is
removed from the host's AP configuration
- Fix loop condition in uv_find_secrets
- Prevent potential out-of-bounds read
x86:
- Fix a brown paper bag bug where KVM would incorrectly treat Intel
PMU MSRs as valid on AMD
- Fix a regression in the hardware disable selftest where it checked
the wrong macro when detecting glibc support (breaks at least musl)
- Never clear KVM_REQ_VM_DEAD so that dead VMs stay dead, which is
especially important for KVM_BUG_ON() flows, which often guard more
dangerous bugs
- Re-pend GET_NESTED_STATE_PAGES if getting the pages fails, to fix a
bug where KVM would let userspace run a broken setup with stale
vmcs12 pages
- Fix a class of bugs where KVM would fail to fill kvm_run exit
fields if getting nested pages failed
- Treat reserved entries in the memory attributes xarray as "no
attributes", to fix false positives when checking for mixed
attributes
- Fix memcg accounting for the memory attributes xarray (the xarray
library subtly requires the xarray to be configured for accounting
upfront; the gfp flags taken at runtime are used only rarely)
- Don't pre-reserve xarray entries when storing empty attributes, as
storing NULL must not require memory allocation (KVM and other
subsystems heavily rely on this behavior)
- Fix a memory leak and a cache maintenance issue related to doing
intra-host migration on an SEV guest"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (54 commits)
KVM: SEV: Do cache maintenance on the source VM during intra-host migration
KVM: SEV: Free have_run_cpus during VM destruction even if VM is no longer SEV
KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes
KVM: Ensure memory attributes xarray nodes are accounted to the caller's memcg
KVM: Don't treat reserved xarray entries as having memory attributes
KVM: x86: Fill kvm_run exit fields in common get_nested_state_pages() error paths
KVM: x86: Re-pend GET_NESTED_STATE_PAGES if getting said pages fails
KVM: arm64: Fix AArch32 DBGBXVR<n> handling
KVM: arm64: Fix FGT mapping for HFGITR_EL2.nGCSEPP
KVM: selftests: fix steal_time for arm64 with host page size > 4K
KVM: arm64: Don't WARN on an unknown VM ioctl in protected mode
KVM: arm64: nv: Delay freeing of shadow S2 structures until VM destruction
KVM: arm64: nv: Fix life cycle of the nested_mmus array
KVM: arm64: Check every private mapping is hyp-owned at pKVM init
KVM: arm64: Move the private VA allocation cursor to __io_map_next
KVM: arm64: Match hyp text by physical address in fix_host_ownership()
KVM: arm64: Transfer the hyp stack pages out of the host stage-2
KVM: arm64: selftests: Test empty SMCCC filter range at base 0
KVM: arm64: Return -EINVAL for an empty SMCCC filter range at base 0
KVM: arm64: Derive GUEST_HAS_SVE from the SVE feature bit at EL2
...
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KVM fixes for 7.3-rcN
- Fix a brown paper bag bug where KVM would incorrectly treat Intel PMU MSRs
as valid on AMD.
- Fix a regression in the hardware disable selftest where it checked the wrong
macro when detecting glibc support (breaks at least musl).
- Never clear KVM_REQ_VM_DEAD so that dead VMs stay dead, which is especially
important for KVM_BUG_ON() flows, which often guard more dangerous bugs.
- Re-pend GET_NESTED_STATE_PAGES if getting the pages fails, to fix a bug
where KVM would let userspace run a broken setup with stale vmcs12 pages.
- Fix a class of bugs where KVM would fail to fill kvm_run exit fields if
getting nested pages failed.
- Treat reserved entries in the memory attributes xarray as "no attributes",
to fix false positives when checking for mixed attributes.
- Fix memcg accounting for the memory attributes xarray (the xarray library
subtly requires the xarray to be configured for accounting upfront; the gfp
flags taken at runtime are used only rarely).
- Don't pre-reserve xarray entries when storing empty attributes, as storing
NULL must not require memory allocation (KVM and other subsystems heavily
rely on this behavior).
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Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.
Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.
Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe
Pull IPE fixes from Fan Wu:
"Two fixes for use-after-free issues found by recent LLM-assisted code
analysis.
- move successful policy load auditing under the new policy
directory's inode lock, preventing a concurrent policy deletion
from freeing the policy while it is still being audited
- protect the dm-verity root hash with RCU, preventing policy
evaluation from racing with root hash replacement during preresume"
* tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe:
ipe: protect the dm-verity root hash with RCU
ipe: fix use-after-free when auditing a newly loaded policy
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Multiple users report data corruption during 64-bit DMA transfers on
systems with AMD NBIO 7.7 and 7.11 controllers.
This occurs when BIOS enables AMD "enhanced atomic operations" on PCIe Root
Ports. When enhanced atomics are enabled, any 64-bit DMA access may be
corrupted.
Disable enhanced atomics using SMN for NBIO 7.7 and 7.11 based models.
Reported-by: Mikael Etienne <mikael1022bzh@gmail.com>
Closes: https://lore.kernel.org/178789300872.392066.15963676631650361573@gmail.com/
Reported-by: Arthur Husband <artmoty@gmail.com>
Closes: https://lore.kernel.org/20260406222335.379935-1-artmoty@gmail.com/
Reported-by: Alvin Lim <alvinwylim@gmail.com>
Closes: https://lore.kernel.org/20260621100844.1224301-1-alvinwylim@gmail.com/
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
[bhelgaas: commit log, s/IOVA/DMA/ in comment]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org
Cc: David Laight <david.laight.linux@gmail.com>
Cc: John Smith <imjohnsmith4000@gmail.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Niklas Cassel <cassel@kernel.org>
Cc: Roland Waltersson <roland.waltersson@netinsight.net>
Link: https://patch.msgid.link/20260908190600.226485-2-mario.limonciello@amd.com
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In exc_machine_check_user(), local_db_save() and local_db_restore() are
invoked in the outer entry stubs (DEFINE_IDTENTRY_MCE_USER,
DEFINE_FREDENTRY_MCE, and DEFINE_IDTENTRY_RAW), surrounding
exc_machine_check_user().
However, exc_machine_check_user() calls irqentry_exit_to_user_mode(), which
handles pending thread work and may schedule() if TIF_NEED_RESCHED is set. If
the task migrates to another CPU during schedule(), local_db_restore() runs on
the new CPU with the dr7 state saved from the old CPU. This corrupts the new
CPU's DR7 hardware debug register and leaves the old CPU's DR7 disabled. In
short, local_db_save() and local_db_restore() pair must be run on the same
CPU.
To fix this, move local_db_save() and local_db_restore() inside
exc_machine_check_user() and exc_machine_check_kernel(). In
exc_machine_check_user(), DR7 is saved and restored strictly around
do_machine_check() to avoid schedule() during migration. In
exc_machine_check_kernel(), local_db_save() is called at the entry point to
prevent early memory accesses from triggering nested #DB exceptions, and
restored on all exits.
Fixes: cd840e424f27 ("x86/entry, mce: Disallow #DB during #MC")
Assisted-by: LLM
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/179005109564.388919.3937970081044095776.stgit@devnote2
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perf_clear_branch_entry_bitfields() clears the bitfields of struct
perf_branch_entry one by one and leaves from/to alone, since callers
overwrite those straight away. The list has to be kept in sync with the
struct by hand and has already fallen behind: new_type and priv were
added to perf_branch_entry and never added here.
Only BRBE writes those two, and neither for every record.
brbe_set_perf_entry_type() leaves new_type alone for a branch type it
does not recognise, and priv is not set for source-only records.
arm_pmuv3.c allocates the per-CPU branch stack with kmalloc(), so such a
record reaches userspace with whatever the slot held: uninitialised
kmalloc() data on the first pass over the buffer, the previous record's
values after that. Nothing under arch/x86/events/ writes either field,
so only arm64 is affected.
Assign the whole entry at each site instead. Everything not named is
then zero, and there is no list to keep in sync. The bitfields add up to
exactly 64 bits, so the struct has no padding to leave undefined.
perf_clear_branch_entry_bitfields() has no callers left, so remove it.
perf_entry_from_brbe_regset() assigns an empty literal instead, since it
fills from/to conditionally. PERF_BR_SPEC_NA is 0, so dropping the
explicit spec assignment changes nothing.
Fixes: b190bc4ac9e6 ("perf: Extend branch type classification")
Fixes: 5402d25aa571 ("perf: Capture branch privilege information")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Yifan Wu <wuyifan50@huawei.com>
Link: https://patch.msgid.link/20260810133540.1947118-4-puranjay@kernel.org
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Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.
Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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NVL introduces Offmodule Response events in place of the legacy
Offcore Response events, but it still exposes the inherited
offcore_rsp PMU attribute for programming the corresponding MSR data.
Rename the NVL PMU attribute to offmodule_rsp so the sysfs interface
matches the underlying event name and avoids user & tooling confusion.
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20260917015234.981153-13-dapeng1.mi@linux.intel.com
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DMR introduces Offmodule Response events in place of the legacy
Offcore Response events, but it still exposes the inherited
offcore_rsp PMU attribute for programming the corresponding MSR data.
Rename the DMR PMU attribute to offmodule_rsp so the sysfs interface
matches the underlying event name and avoids user & tooling confusion.
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20260917015234.981153-12-dapeng1.mi@linux.intel.com
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Two functions in the SVSM vTPM guest implementation do not disable
preemption when fetching the SVSM Calling Area Address (CAA).
The SVSM CAA is a per-CPU structure. When a thread is preempted and migrated
to a different CPU after fetching the per-CPU CAA, the SVSM call will execute
on the new CPU with the original CPU's CAA. Which is wrong.
Move the CAA fetching operation inside svsm_perform_call_protocol() which
disables interrupts around the SVSM call and thus runs preemption-safe.
Fixes: 770de678bc28 ("x86/sev: Add SVSM vTPM probe/send_command functions")
Signed-off-by: Melody Wang <huibo.wang@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/a5bc0d4a2c462a0089109e145c21626b244b2ff0.1789345277.git.huibo.wang@amd.com
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
- Reject the loading of a potentially problematic microcode version
on Intel Granite Rapids systems (Chang S. Bae)
- On FRED, reconstruct the proper #GP context for rejected INT
instructions, to fix a signal ABI regression (Matthew Schwartz)
- Add a test for this signal ABI regression the x86
self-test suite (Matthew Schwartz)
- Don't emit the new and not yet properly supported EGPR instructions
(%r16-%r31) on CONFIG_X86_NATIVE_CPU=y builds (Chang S. Bae)
* tag 'x86-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/build/64: Prevent native builds from generating EGPR use
selftests/x86: Check signal state for rejected software interrupts
x86/fred: Reconstruct the #GP context for rejected INT instructions
x86/microcode/intel: Reject problematic loading on Granite Rapids systems
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events fixes from Ingo Molnar:
- Fix crash when probing CS CALL instructions (Jinke Han)
- Fix NULL pointer crash during module unload (Vinay Belgaumkar)
* tag 'perf-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix null pointer access in is_include_guest_event()
x86/kprobes: Fix crash when probing CS CALL instructions
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull futex fix from Ingo Molnar:
- Also allocate a default private futex hash on vfork() as well, to
avoid races with (private) futex waiters (Peter Zijlstra)
* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Also allocate private hash on vfork()
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Omar reports that CONFIG_X86_NATIVE_CPU=y allows builds to opportunistically
emit instructions using %r16-%r31 (EGPRs) when the build host supports APX
since the commit:
ea1dcca1de12 ("x86/kbuild/64: Add the CONFIG_X86_NATIVE_CPU option to locally optimize the kernel with '-march=native'")
But the kernel is not yet prepared to use new registers internally. For
example, there is no context-switch support for general in-kernel use.
Explicitly disable EGPR use when building with -march=native.
For C, since GCC 14 and Clang 18, both compilers support suppressing EGPR
use with -mno-apx-features=egpr, whose availability can be detected via
cc-option.
For Rust, pass features=-apxf through the generated JSON to avoid
unstable-feature warnings, see
https://github.com/rust-lang/rust/issues/139284
Note Rust only accepts the option to disable APX instructions entirely or not.
Support for this gating also depends on the Rust/LLVM combination. Rust
1.88 introduced the `apxf` feature option, but versions prior to 1.93 may
emit an `apxf` attribute to the backend that only LLVM 23 or later can
interpret. Restrict native Rust builds accordingly.
Fixes: ea1dcca1de12 ("x86/kbuild/64: Add the CONFIG_X86_NATIVE_CPU option to locally optimize the kernel with '-march=native'")
Reported-by: Omar Avelar <omar.avelar@intel.com>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260916230003.1144622-1-chang.seok.bae@intel.com
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FRED event delivery does not use the IDT, so the gate DPL check that
rejects a user INT n falls to software (Intel FRED specification [1],
section 8.3). fred_intx() rejects the same vectors as IDT delivery, but
reports a zero error code and the IP after the INT. This breaks the
signal ABI. Wine uses the error code to recognize INT 0x2d, so the
changed context turns a handled breakpoint into an access violation in
Elden Ring.
Rewind IP using the instruction length in the augmented SS and
synthesize the IDT selector error code, (vector << 3) | 2. Set RF in the
saved flags, as the CPU does for a #GP fault. Section 5.2.1 defines the
saved vector, instruction length and RF state. The supplied length
handles prefixes without reading user memory. Limit the changes to
already-rejected software interrupts, preserving the accepted INT3, INT4
and enabled INT80 paths and hardware exceptions. With IA32 emulation
disabled, INT 0x80 now reports the same #GP as the DPL 0 gate IDT
installs there. The rewound IP also stops fixup_iopl_exception() from
inspecting the byte after the INT.
Also clear the software event flag. Section 6.2.3 specifies that ERETU
with this flag and TF set traps before executing any user instruction. A
tracer that suppresses SIGSEGV and resumes with TF set expects the next
instruction to run first, as after IRET. The sigreturn path clears the
same flag for this reason in prevent_single_step_upon_eretu().
[1] Intel Flexible Return and Event Delivery (FRED) Specification,
revision 9.0 (346446-009US), sections 5.2.1, 6.2.3 and 8.3.
Fixes: 14619d912b65 ("x86/fred: FRED entry/exit and dispatch code")
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/work_items/15745
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/work_items/16132
Reported-by: Paul Gofman <pgofman@codeweavers.com>
Signed-off-by: Matthew Schwartz <matthew.schwartz@linux.dev>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Link: https://cdrdv2.intel.com/v1/dl/getContent/678938 # [1]
Link: https://patch.msgid.link/20260917230907.2080792-2-matthew.schwartz@linux.dev
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Microcode updates can usually jump revisions. However, there is an erratum on
Granite Rapids systems. If they "jump over" revision 0x1000405, they result in
an #MC. Avoid it.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260916225939.1144524-1-chang.seok.bae@intel.com
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When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.
The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:
<__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>: mov %r14,%rdi
<__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>: mov %eax,%r12d
<__hrtimer_run_queues+266>: xchg %ax,%ax
<__hrtimer_run_queues+268>: mov %r13,%rdi
Which triggers this crash:
BUG: unable to handle page fault for address: 00000000000f41c9
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] SMP NOPTI
CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
RIP: 0010:__hrtimer_run_queues+0x106/0x230
Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.
The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.
During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.
Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.
[ mingo: Refined the changelog ]
Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000
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The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.
Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.
Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.
Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.
Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix error output of boot instance creation failure
Currently if a boot instance creation fails, instead of printing out
the name of the instance that failed, it prints "(null)". That is
because it prints "cur_str" that had already been processed by
strsep(). Print the saved name instead.
While at it, print the error code of the failure.
- Fix use-after-free for same named historgrams
Histograms can be named so that they can be used in multiple events.
But if the named histogram has a variable attached, the second event
that uses the named histogram which duplicates it and needs to free
the original after duplication leaves the old variable in place and
still visible. If another histogram uses than variable, it will use
the stale one which will try to reference the freed duplicate
histogram and crash the kernel.
Free the duplicate variables along with the duplicated histogram
data.
- Check return value of kthread_run() in event self test
The events self tests uses a kthread for testing but does not check
if it succeeded in creating a kthread. If the kthread creation were
to fail, the code will still try to call kthread_stop() on the error
returned.
- Fix race between reading trace_pipe and updating subbuffer size
If a user is reading the trace_pipe file at the same time they update
the ring buffer sub-buffer size, can cause the trace_pipe read to
read stale data. Add trace_access_lock() around updating the ring
buffer sub-buffer size.
- Fix eventfs_inode on failure path in creation of the events directory
In the creation of the "events" directory, if after allocating the
eventfs_inode a failure is detected, it calls cleanup_ei() which
calls free_ei(). The free_ei() will test if eventfs_inode being freed
has no children. It is a bug if it does. But on the failure case of
the creation of the "events" directory, the children lists have not
yet been initialized and the free will trigger a warning because
list_empty() on an uninitialized list returns false.
Move the initialization into init_ei() where it makes more sense and
makes sure that a created eventfs_inode has its lists initialized
upon creation.
- Check return value of kthread_run() in ftrace direct sample code
The sample code that shows how to use the ftrace direct calls does
not test the return of kthread_run() to see if it succeeds. Return a
failure if the kthread_run() doesn't succeed.
- Clear user events state on fork in case of alloc failure
On fork, the child gets a pointer to the parent's user events state.
It makes a copy of it then updates the child's pointer to it. But if
the allocation fails, the duplication function leaves the child with
a pointer to its parent's descriptor. When the child cleans up its
data, it will free the parent's descriptor while the parent is still
using it.
In the duplication function, set the child's user_event_mm to NULL
before testing if the allocation succeeded, and when it exits it will
not free the parent's descriptor.
- Fix retry exhaustion in simple ring buffer reader swap
simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
post-decrements it only after a failed link replacement. On the final
attempt, a successful replacement leaves retry at zero, while a
failed replacement leaves it at -1.
But the check for success expects the retry value to be non-zero and
exits with an error on zero. This is the opposite result. Fix it.
- Fail nicely when the remote swap_reader_page() returns an error
Currently, if the swap_reader_page() of a remote buffer fails, it
triggers a WARN_ON_ONCE() and continues normally. Instead, have it
exit with an error and a pr_warn() print instead of a full WARNING.
* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Stop remote reader update when page swap fails
tracing: Fix retry exhaustion in simple ring buffer reader swap
tracing/user_events: Clear copied tracing state before fork duplication
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
eventfs: Initialize ei->children and ei->list in init_ei()
tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
tracing: Fix crash passing ERR_PTR to kthread_stop()
tracing: Fix use-after-free with same-name named triggers
tracing: Fix logged instance name on creation failure
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