[PATCH AUTOSEL 4.19 148/206] KVM: arm64: vgic-its: Fix memory leak on the error path of vgic_add_lpi()

[Sasha Levin]

From: Zenghui Yu <yuzenghui@xxxxxxxxxx>

[ Upstream commit 57bdb436ce869a45881d8aa4bc5dac8e072dd2b6 ]

If we're going to fail out the vgic_add_lpi(), let's make sure the
allocated vgic_irq memory is also freed. Though it seems that both
cases are unlikely to fail.

Signed-off-by: Zenghui Yu <yuzenghui@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200414030349.625-3-yuzenghui@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 virt/kvm/arm/vgic/vgic-its.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 9295addea7ecf..f139b1c62ca38 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -107,14 +107,21 @@ out_unlock:
 	 * We "cache" the configuration table entries in our struct vgic_irq's.
 	 * However we only have those structs for mapped IRQs, so we read in
 	 * the respective config data from memory here upon mapping the LPI.
+	 *
+	 * Should any of these fail, behave as if we couldn't create the LPI
+	 * by dropping the refcount and returning the error.
 	 */
 	ret = update_lpi_config(kvm, irq, NULL, false);
-	if (ret)
+	if (ret) {
+		vgic_put_irq(kvm, irq);
 		return ERR_PTR(ret);
+	}
 
 	ret = vgic_v3_lpi_sync_pending_status(kvm, irq);
-	if (ret)
+	if (ret) {
+		vgic_put_irq(kvm, irq);
 		return ERR_PTR(ret);
+	}
 
 	return irq;
 }
-- 
2.25.1