Commit 740a1931 authored Jun 13, 2019 by Philippe Mathieu-Daudé Committed by David Gibson Jul 02, 2019

spapr_pci: Fix potential NULL pointer dereference in spapr_dt_pci_bus()



Commit 14e71490 refactored the call to spapr_dt_drc(),
introducing a potential NULL pointer dereference while
accessing bus->parent_dev.
A trivial audit show 'bus' is not null in the two places
the static function spapr_dt_drc() is called.

Since the 'bus' parameter is not NULL in both callers, remove
remove the test on if (bus), and add an assert() to silent
static analyzers.

This fixes:

  /hw/ppc/spapr_pci.c: 1367 in spapr_dt_pci_bus()
  >>>     CID 1401933:  Null pointer dereferences  (FORWARD_NULL)
  >>>     Dereferencing null pointer "bus".
  1367         ret = spapr_dt_drc(fdt, offset, OBJECT(bus->parent_dev),
  1368                            SPAPR_DR_CONNECTOR_TYPE_PCI);

Fixes: 14e71490
Reported-by: Coverity (CID 1401933)
Suggested-by: Greg Kurz <groug@kaod.org>
Suggested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190613213406.22053-1-philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

parent c29a0b0f

hw/ppc/spapr_pci.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -1356,13 +1356,12 @@ static int spapr_dt_pci_bus(SpaprPhbState sphb, PCIBus bus,
		_FDT(fdt_setprop_cell(fdt, offset, "#size-cells",
		RESOURCE_CELLS_SIZE));

		if (bus) {
		assert(bus);
		pci_for_each_device_reverse(bus, pci_bus_num(bus),
		spapr_dt_pci_device_cb, &cbinfo);
		if (cbinfo.err) {
		return cbinfo.err;
		}
		}

		ret = spapr_dt_drc(fdt, offset, OBJECT(bus->parent_dev),
		SPAPR_DR_CONNECTOR_TYPE_PCI);