The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From c507babf10ead4d5c8cca704539b170752a8ac84 Mon Sep 17 00:00:00 2001
From: Punit Agrawal <punit.agrawal@xxxxxxx>
Date: Thu, 4 Jan 2018 18:24:33 +0000
Subject: [PATCH] KVM: arm/arm64: Check pagesize when allocating a hugepage at
Stage 2
KVM only supports PMD hugepages at stage 2 but doesn't actually check
that the provided hugepage memory pagesize is PMD_SIZE before populating
stage 2 entries.
In cases where the backing hugepage size is smaller than PMD_SIZE (such
as when using contiguous hugepages), KVM can end up creating stage 2
mappings that extend beyond the supplied memory.
Fix this by checking for the pagesize of userspace vma before creating
PMD hugepage at stage 2.
Fixes: 66b3923a1a0f77a ("arm64: hugetlb: add support for PTE contiguous bit")
Signed-off-by: Punit Agrawal <punit.agrawal@xxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v4.5+
Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index b4b69c2d1012..9dea96380339 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1310,7 +1310,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return -EFAULT;
}
- if (is_vm_hugetlb_page(vma) && !logging_active) {
+ if (vma_kernel_pagesize(vma) == PMD_SIZE && !logging_active) {
hugetlb = true;
gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
} else {