[PATCH 1/5] KVM: e500: retry if no memslot is found

[Paolo Bonzini]

Avoid a NULL pointer dereference if the memslot table changes between the
exit and the call to kvmppc_e500_shadow_map().

Cc: stable at vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
---
 arch/powerpc/kvm/e500_mmu_host.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index e5a145b578a4..732335444d68 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -349,6 +349,11 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 	 * pointer through from the first lookup.
 	 */
 	slot = gfn_to_memslot(vcpu_e500->vcpu.kvm, gfn);
+	if (!slot) {
+		ret = -EAGAIN;
+		goto out;
+	}
+
 	hva = gfn_to_hva_memslot(slot, gfn);
 
 	if (tlbsel == 1) {
-- 
2.47.1