From: Eric Auger <eric.auger@redhat.com>
Date: Tue, 22 May 2018 09:55:06 +0200
Subject: KVM: arm/arm64: Set dist->spis to NULL after kfree
Patch-mainline: v4.18-rc1
Git-commit: 9153ab724ea1f47840cab0cedb12683b37272067
References: bsc#1133021

in case kvm_vgic_map_resources() fails, typically if the vgic
distributor is not defined, __kvm_vgic_destroy will be called
several times. Indeed kvm_vgic_map_resources() is called on
first vcpu run. As a result dist->spis is freeed more than once
and on the second time it causes a "kernel BUG at mm/slub.c:3912!"

Set dist->spis to NULL to avoid the crash.

Fixes: ad275b8bb1e6 ("KVM: arm/arm64: vgic-new: vgic_init: implement
vgic_init")

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Liang Yan <lyan@suse.com>
---
 virt/kvm/arm/vgic/vgic-init.c |    1 +
 1 file changed, 1 insertion(+)

--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -325,6 +325,7 @@ static void kvm_vgic_dist_destroy(struct
 	dist->initialized = false;
 
 	kfree(dist->spis);
+	dist->spis = NULL;
 	dist->nr_spis = 0;
 
 	if (vgic_supports_direct_msis(kvm))