<gregkh@xxxxxxxxxxxxxxxxxxx> writes:
> 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>.
The fix didn't apply as the file has moved recently. I am including the
backport below.
I left the tags from the original commit intact as there's no real
change - hope that's ok.
Apologies for the trouble.
Thanks,
Punit
------->8------
>From db0a288ba58478461d53a5f98878f59e65a9345f Mon Sep 17 00:00:00 2001
From: Punit Agrawal <punit.agrawal@xxxxxxx>
Date: Mon, 22 Jan 2018 11:11:05 +0000
Subject: [PATCH] KVM: arm/arm64: Check pagesize when allocating a hugepage at
Stage 2
Backport of commit c507babf10ead4d5c8cca704539b170752a8ac84 upstream.
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>
Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
---
arch/arm/kvm/mmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 2206e0e00934..2a35c1963f6d 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -1284,7 +1284,7 @@ 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) && !logging_active) {
hugetlb = true;
gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
} else {
--
2.15.1