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 4.14-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-4.14 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> --- virt/kvm/arm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1310,7 +1310,7 @@ static int user_mem_abort(struct kvm_vcp 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 { Patches currently in stable-queue which might be from punit.agrawal@xxxxxxx are queue-4.14/kvm-arm-arm64-check-pagesize-when-allocating-a-hugepage-at-stage-2.patch