This is a note to let you know that I've just added the patch titled
KVM: arm/arm64: Check pagesize when allocating a hugepage at Stage 2
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-arm-arm64-check-pagesize-when-allocating-a-hugepage-at-stage-2.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>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: KVM: arm/arm64: Check pagesize when allocating a hugepage at Stage 2
From: Punit Agrawal <punit.agrawal@xxxxxxx>
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>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/kvm/mmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -1284,7 +1284,7 @@ static int user_mem_abort(struct kvm_vcp
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 {
Patches currently in stable-queue which might be from punit.agrawal@xxxxxxx are
queue-4.9/kvm-arm-arm64-check-pagesize-when-allocating-a-hugepage-at-stage-2.patch