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| author | Oliver Upton <oliver.upton@linux.dev> | 2023-05-30 19:32:13 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2023-05-31 08:02:21 +0100 |
| commit | f6a27d6dc51b288106adaf053cff9c9b9cc12c4e (patch) | |
| tree | 3df9b9c30b6c53cfb038014fa6d98b7753230611 | |
| parent | 811154e234db72f0a11557a84ba9640f8b3bc823 (diff) | |
| download | iio-f6a27d6dc51b288106adaf053cff9c9b9cc12c4e.tar.gz | |
KVM: arm64: Drop last page ref in kvm_pgtable_stage2_free_removed()
The reference count on page table allocations is increased for every
'counted' PTE (valid or donated) in the table in addition to the initial
reference from ->zalloc_page(). kvm_pgtable_stage2_free_removed() fails
to drop the last reference on the root of the table walk, meaning we
leak memory.
Fix it by dropping the last reference after the free walker returns,
at which point all references for 'counted' PTEs have been released.
Cc: stable@vger.kernel.org
Fixes: 5c359cca1faf ("KVM: arm64: Tear down unlinked stage-2 subtree after break-before-make")
Reported-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Tested-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230530193213.1663411-1-oliver.upton@linux.dev
| -rw-r--r-- | arch/arm64/kvm/hyp/pgtable.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index e1eacffbc41f4..95dae02ccc2e6 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -1332,4 +1332,7 @@ void kvm_pgtable_stage2_free_removed(struct kvm_pgtable_mm_ops *mm_ops, void *pg }; WARN_ON(__kvm_pgtable_walk(&data, mm_ops, ptep, level + 1)); + + WARN_ON(mm_ops->page_count(pgtable) != 1); + mm_ops->put_page(pgtable); } |