diff options
| author | Ingo Molnar <mingo@elte.hu> | 2007-01-06 01:36:59 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2007-01-06 08:55:28 +0100 |
| commit | d21225ee2b6fa9f7669526927f2e0bedebd90940 (patch) | |
| tree | c606fa6b98a7f30215bb8702fd5e22d1d4123589 | |
| parent | [PATCH] KVM: MMU: Add missing dirty bit (diff) | |
| download | linux-d21225ee2b6fa9f7669526927f2e0bedebd90940.tar.xz linux-d21225ee2b6fa9f7669526927f2e0bedebd90940.zip | |
[PATCH] KVM: Make loading cr3 more robust
Prevent the guest's loading of a corrupt cr3 (pointing at no guest phsyical
page) from crashing the host.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | drivers/kvm/kvm_main.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 0675d3e51692..67c1154960f0 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -463,7 +463,19 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) vcpu->cr3 = cr3; spin_lock(&vcpu->kvm->lock); - vcpu->mmu.new_cr3(vcpu); + /* + * Does the new cr3 value map to physical memory? (Note, we + * catch an invalid cr3 even in real-mode, because it would + * cause trouble later on when we turn on paging anyway.) + * + * A real CPU would silently accept an invalid cr3 and would + * attempt to use it - with largely undefined (and often hard + * to debug) behavior on the guest side. + */ + if (unlikely(!gfn_to_memslot(vcpu->kvm, cr3 >> PAGE_SHIFT))) + inject_gp(vcpu); + else + vcpu->mmu.new_cr3(vcpu); spin_unlock(&vcpu->kvm->lock); } EXPORT_SYMBOL_GPL(set_cr3); |