[PATCH] KVM: vgic: Fix potential double free dist->spis in __kvm_vgic_destroy()

From: linmiaohe
Date: Thu Nov 28 2019 - 01:39:00 EST


From: Miaohe Lin <linmiaohe@xxxxxxxxxx>

In kvm_vgic_dist_init() called from kvm_vgic_map_resources(), if
dist->vgic_model is invalid, dist->spis will be freed without set
dist->spis = NULL. And in vgicv2 resources clean up path,
__kvm_vgic_destroy() will be called to free allocated resources.
And dist->spis will be freed again in clean up chain because we
forget to set dist->spis = NULL in kvm_vgic_dist_init() failed
path. So double free would happen.

Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
virt/kvm/arm/vgic/vgic-init.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 53e3969dfb52..c17c29beeb72 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -171,6 +171,7 @@ static int kvm_vgic_dist_init(struct kvm *kvm, unsigned int nr_spis)
break;
default:
kfree(dist->spis);
+ dist->spis = NULL;
return -EINVAL;
}
}
--
2.19.1