FAILED: patch "[PATCH] KVM: arm/arm64: Check pagesize when allocating a hugepage at" failed to apply to 4.9-stable tree

FAILED: patch "[PATCH] KVM: arm/arm64: Check pagesize when allocating a hugepage at" failed to apply to 4.9-stable tree

[gregkh]

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@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From c507babf10ead4d5c8cca704539b170752a8ac84 Mon Sep 17 00:00:00 2001
From: Punit Agrawal <punit.agrawal@arm.com>
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@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: <stable@vger.kernel.org> # v4.5+
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

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 {

Re: FAILED: patch "[PATCH] KVM: arm/arm64: Check pagesize when allocating a hugepage at" failed to apply to 4.9-stable tree

[Punit Agrawal]

<gregkh@linuxfoundation.org> 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@vger.kernel.org>.

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@arm.com>
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@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 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

Re: FAILED: patch "[PATCH] KVM: arm/arm64: Check pagesize when allocating a hugepage at" failed to apply to 4.9-stable tree

[Punit Agrawal]

<gregkh@linuxfoundation.org> 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@vger.kernel.org>.

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@arm.com>
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@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 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

Re: FAILED: patch "[PATCH] KVM: arm/arm64: Check pagesize when allocating a hugepage at" failed to apply to 4.9-stable tree

[Greg KH]

On Mon, Jan 22, 2018 at 11:47:13AM +0000, Punit Agrawal wrote:
> <gregkh@linuxfoundation.org> 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@vger.kernel.org>.
> 
> 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.

Not a problem, thanks for the patch, now queued up.

greg k-h