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[nvidia-jp7] KVM: x86: Fix shadow paging use-after-free due to unexpected role (CVE-2026-53359) #266

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Merged
rene merged 3 commits into from
Jul 17, 2026
Merged

[nvidia-jp7] KVM: x86: Fix shadow paging use-after-free due to unexpected role (CVE-2026-53359) #266

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bb0c2de
KVM: x86: Fix shadow paging use-after-free due to unexpected GFN
sean-jc Apr 15, 2026
2846661
KVM: x86: Fix shadow paging use-after-free due to unexpected role
bonzini Jun 12, 2026
c93c896
Makefile.eve: make linuxkit tmp dir user-specific
christoph-zededa Jul 14, 2026
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4 changes: 2 additions & 2 deletions Makefile.eve
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Original file line number Diff line number Diff line change
Expand Up @@ -30,9 +30,9 @@ LINUXKIT_GIT_REF ?= 3bf33c3a11fc20b459195294a7d8980cbca4195b

ifneq ($(LINUXKIT_GIT_URL),)
_LK_VERSION := $(shell printf '%s' '$(LINUXKIT_GIT_REF)' | cut -c1-12)
LK := /tmp/linuxkit-$(_LK_VERSION)
LK := /tmp/linuxkit-$(_LK_VERSION)-$(USER)
else
LK := /tmp/linuxkit-$(LINUXKIT_VERSION)
LK := /tmp/linuxkit-$(LINUXKIT_VERSION)-$(USER)
endif

SOURCE_DATE_EPOCH=$(shell git log -1 --format=%ct)
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41 changes: 18 additions & 23 deletions kernel/kernel-noble/arch/x86/kvm/mmu/mmu.c
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Original file line number Diff line number Diff line change
Expand Up @@ -182,6 +182,8 @@ struct kmem_cache *mmu_page_header_cache;
static struct percpu_counter kvm_total_used_mmu_pages;

static void mmu_spte_set(u64 *sptep, u64 spte);
static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
u64 *spte, struct list_head *invalid_list);

struct kvm_mmu_role_regs {
const unsigned long cr0;
Expand Down Expand Up @@ -1200,19 +1202,6 @@ static void drop_spte(struct kvm *kvm, u64 *sptep)
rmap_remove(kvm, sptep);
}

static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush)
{
struct kvm_mmu_page *sp;

sp = sptep_to_sp(sptep);
WARN_ON_ONCE(sp->role.level == PG_LEVEL_4K);

drop_spte(kvm, sptep);

if (flush)
kvm_flush_remote_tlbs_sptep(kvm, sptep);
}

/*
* Write-protect on the specified @sptep, @pt_protect indicates whether
* spte write-protection is caused by protecting shadow page table.
Expand Down Expand Up @@ -2354,12 +2343,15 @@ static struct kvm_mmu_page *kvm_mmu_get_child_sp(struct kvm_vcpu *vcpu,
u64 *sptep, gfn_t gfn,
bool direct, unsigned int access)
{
union kvm_mmu_page_role role;
union kvm_mmu_page_role role = kvm_mmu_child_role(sptep, direct, access);

if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep))
if (is_shadow_present_pte(*sptep) &&
!is_large_pte(*sptep) &&
spte_to_child_sp(*sptep) &&
spte_to_child_sp(*sptep)->gfn == gfn &&
spte_to_child_sp(*sptep)->role.word == role.word)
return ERR_PTR(-EEXIST);

role = kvm_mmu_child_role(sptep, direct, access);
return kvm_mmu_get_shadow_page(vcpu, gfn, role);
}

Expand Down Expand Up @@ -2434,13 +2426,16 @@ static void __link_shadow_page(struct kvm *kvm,

BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK);

/*
* If an SPTE is present already, it must be a leaf and therefore
* a large one. Drop it, and flush the TLB if needed, before
* installing sp.
*/
if (is_shadow_present_pte(*sptep))
drop_large_spte(kvm, sptep, flush);
if (is_shadow_present_pte(*sptep)) {
struct kvm_mmu_page *parent_sp;
LIST_HEAD(invalid_list);

parent_sp = sptep_to_sp(sptep);
WARN_ON_ONCE(parent_sp->role.level == PG_LEVEL_4K);

mmu_page_zap_pte(kvm, parent_sp, sptep, &invalid_list);
kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, true);
}

spte = make_nonleaf_spte(sp->spt, sp_ad_disabled(sp));

Expand Down