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| author | Sebastian Ott <sebott@redhat.com> | 2025-05-05 20:31:48 +0300 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2025-05-05 22:12:27 +0300 |
| commit | 157dbc4a321f5bb6f8b6c724d12ba720a90f1a7c (patch) | |
| tree | eec83e760417c9711a719ac8fa42a7e3924746be | |
| parent | b4432656b36e5cc1d50a1f2dc15357543add530e (diff) | |
| download | linux-157dbc4a321f5bb6f8b6c724d12ba720a90f1a7c.tar.xz | |
KVM: arm64: Fix uninitialized memcache pointer in user_mem_abort()
Commit fce886a60207 ("KVM: arm64: Plumb the pKVM MMU in KVM") made the
initialization of the local memcache variable in user_mem_abort()
conditional, leaving a codepath where it is used uninitialized via
kvm_pgtable_stage2_map().
This can fail on any path that requires a stage-2 allocation
without transition via a permission fault or dirty logging.
Fix this by making sure that memcache is always valid.
Fixes: fce886a60207 ("KVM: arm64: Plumb the pKVM MMU in KVM")
Signed-off-by: Sebastian Ott <sebott@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/kvmarm/3f5db4c7-ccce-fb95-595c-692fa7aad227@redhat.com/
Link: https://lore.kernel.org/r/20250505173148.33900-1-sebott@redhat.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
| -rw-r--r-- | arch/arm64/kvm/mmu.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 754f2fe0cc67..eeda92330ade 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1501,6 +1501,11 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, return -EFAULT; } + if (!is_protected_kvm_enabled()) + memcache = &vcpu->arch.mmu_page_cache; + else + memcache = &vcpu->arch.pkvm_memcache; + /* * Permission faults just need to update the existing leaf entry, * and so normally don't require allocations from the memcache. The @@ -1510,13 +1515,11 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (!fault_is_perm || (logging_active && write_fault)) { int min_pages = kvm_mmu_cache_min_pages(vcpu->arch.hw_mmu); - if (!is_protected_kvm_enabled()) { - memcache = &vcpu->arch.mmu_page_cache; + if (!is_protected_kvm_enabled()) ret = kvm_mmu_topup_memory_cache(memcache, min_pages); - } else { - memcache = &vcpu->arch.pkvm_memcache; + else ret = topup_hyp_memcache(memcache, min_pages); - } + if (ret) return ret; } |