From 45258bdd7f2da471c1201443a63765eff1622863 Mon Sep 17 00:00:00 2001 From: Marek Majtyka Date: Wed, 16 Sep 2015 12:04:55 +0200 Subject: arm: KVM: Fix incorrect device to IPA mapping [ Upstream commit ca09f02f122b2ecb0f5ddfc5fd47b29ed657d4fd ] A critical bug has been found in device memory stage1 translation for VMs with more then 4GB of address space. Once vm_pgoff size is smaller then pa (which is true for LPAE case, u32 and u64 respectively) some more significant bits of pa may be lost as a shift operation is performed on u32 and later cast onto u64. Example: vm_pgoff(u32)=0x00210030, PAGE_SHIFT=12 expected pa(u64): 0x0000002010030000 produced pa(u64): 0x0000000010030000 The fix is to change the order of operations (casting first onto phys_addr_t and then shifting). Reviewed-by: Marc Zyngier [maz: fixed changelog and patch formatting] Cc: stable@vger.kernel.org Signed-off-by: Marek Majtyka Signed-off-by: Marc Zyngier Signed-off-by: Sasha Levin --- arch/arm/kvm/mmu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index cba52cf6ed3f..3535480e0e6b 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1439,8 +1439,10 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, if (vma->vm_flags & VM_PFNMAP) { gpa_t gpa = mem->guest_phys_addr + (vm_start - mem->userspace_addr); - phys_addr_t pa = (vma->vm_pgoff << PAGE_SHIFT) + - vm_start - vma->vm_start; + phys_addr_t pa; + + pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT; + pa += vm_start - vma->vm_start; ret = kvm_phys_addr_ioremap(kvm, gpa, pa, vm_end - vm_start, -- cgit v1.2.3