[PATCH gmem] KVM: Fix off-by-one error when querying attributes in xarray

From: Sean Christopherson
Date: Mon Oct 23 2023 - 16:35:42 EST


Subtract -1 from kvm_range_has_memory_attributes()'s @end when using
xas_find(), as "end" is exclusive whereas xas_find() takes an inclusive
"max" as the maximal index to find/return.

Reported-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
virt/kvm/kvm_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 959e866c84f0..12458959dd25 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2447,7 +2447,7 @@ bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end,
rcu_read_lock();

if (!attrs) {
- has_attrs = !xas_find(&xas, end);
+ has_attrs = !xas_find(&xas, end - 1);
goto out;
}


base-commit: 911b515af3ec5f53992b9cc162cf7d3893c2fbe2
--
2.42.0.758.gaed0368e0e-goog