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Subject[PATCH v2 2/2] Revert "KVM: x86: work around leak of uninitialized stack contents"
Date
handle_vmptrst()/handle_vmread() stopped injecting #PF unconditionally
and switched to nested_vmx_handle_memory_failure() which just kills the
guest with KVM_EXIT_INTERNAL_ERROR in case of MMIO access, zeroing
'exception' in kvm_write_guest_virt_system() is not needed anymore.

This reverts commit 541ab2aeb28251bf7135c7961f3a6080eebcc705.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/x86.c | 7 -------
1 file changed, 7 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9e41b5135340..0097a97d331f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5647,13 +5647,6 @@ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,
/* kvm_write_guest_virt_system can pull in tons of pages. */
vcpu->arch.l1tf_flush_l1d = true;

- /*
- * FIXME: this should call handle_emulation_failure if X86EMUL_IO_NEEDED
- * is returned, but our callers are not ready for that and they blindly
- * call kvm_inject_page_fault. Ensure that they at least do not leak
- * uninitialized kernel stack memory into cr2 and error code.
- */
- memset(exception, 0, sizeof(*exception));
return kvm_write_guest_virt_helper(addr, val, bytes, vcpu,
PFERR_WRITE_MASK, exception);
}
--
2.25.4
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