The 'isapc' machine type has no PCI bus, but pc_nic_init() still
calls pci_init_nic_devices() passing it a NULL bus pointer. This
causes the clang sanitizer to complain:
$ ./build/clang/qemu-system-i386 -M isapc
../../hw/pci/pci.c:1866:39: runtime error: member access within null pointer of
type 'PCIBus' (aka 'struct PCIBus')
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
../../hw/pci/pci.c:1866:39 in
This is because pci_init_nic_devices() does
&bus->qbus
which is undefined behaviour on a NULL pointer even though we're not
actually dereferencing the pointer. (We don't actually crash as
a result, so if you aren't running a sanitizer build then there
are no user-visible effects.)
Make pc_nic_init() avoid trying to initialize PCI NICs on a non-PCI
system.
Cc: qemu-sta...@nongnu.org
Fixes: 8d39f9ba14d64 ("hw/i386/pc: use qemu_get_nic_info() and
pci_init_nic_devices()")
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
---
This shows up if you run "make check" on a ubsan build.
---
hw/i386/pc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 2047633e4cf..1af1a1a1823 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1251,7 +1251,9 @@ void pc_nic_init(PCMachineClass *pcmc, ISABus *isa_bus,
PCIBus *pci_bus)
}
/* Anything remaining should be a PCI NIC */
- pci_init_nic_devices(pci_bus, mc->default_nic);
+ if (pci_bus) {
+ pci_init_nic_devices(pci_bus, mc->default_nic);
+ }
rom_reset_order_override();
}
--
2.34.1
