From bc9b1f10f29dd7e717e6b5a050cbe5fbe8537200 Mon Sep 17 00:00:00 2001
From: Greg Kurz <groug@kaod.org>
Date: Fri, 24 Aug 2018 17:30:04 +0200
Subject: [PATCH] spapr_pci: fix potential NULL pointer dereference
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Commit 2c88b098e76fd added a call to SPAPR_MACHINE_GET_CLASS(spapr) in
spapr_phb_realize() before we check spapr isn't NULL. This causes QEMU
to crash when starting a non-pseries machine with a sPAPR PHB.
This could be fixed by setting the smc variable after the null check,
but it seems more explicit to use a ternary operator to skip the call
to SPAPR_MACHINE_GET_CLASS() if spapr is NULL, since spapr_phb_realize()
will return immediately in this case.
This was reported by Coverity (CID 1395170 and 1395183).
Fixes: 2c88b098e76fde0c7fcc0476dd3f80ce58409505
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
hw/ppc/spapr_pci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 5cd676e443..6bcb4f419b 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -1559,7 +1559,7 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
sPAPRMachineState *spapr =
(sPAPRMachineState *) object_dynamic_cast(qdev_get_machine(),
TYPE_SPAPR_MACHINE);
- sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
+ sPAPRMachineClass *smc = spapr ? SPAPR_MACHINE_GET_CLASS(spapr) : NULL;
SysBusDevice *s = SYS_BUS_DEVICE(dev);
sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
PCIHostState *phb = PCI_HOST_BRIDGE(s);
--
2.30.2