summary refs log tree commit diff stats
path: root/hw/acpi/pcihp.c
diff options
context:
space:
mode:
authorMichael S. Tsirkin <mst@redhat.com>2021-12-21 09:45:44 -0500
committerMichael S. Tsirkin <mst@redhat.com>2022-01-06 06:11:38 -0500
commit9bd6565ccee68f72d5012e24646e12a1c662827e (patch)
treed4759ce3d001818e49cfe7adf0d22c220fa28d69 /hw/acpi/pcihp.c
parent7656d9ce09cb1d6d76eeb2081f164a920361d1d3 (diff)
downloadfocaccia-qemu-9bd6565ccee68f72d5012e24646e12a1c662827e.tar.gz
focaccia-qemu-9bd6565ccee68f72d5012e24646e12a1c662827e.zip
acpi: validate hotplug selector on access
When bus is looked up on a pci write, we didn't
validate that the lookup succeeded.
Fuzzers thus can trigger QEMU crash by dereferencing the NULL
bus pointer.

Fixes: b32bd763a1 ("pci: introduce acpi-index property for PCI device")
Fixes: CVE-2021-4158
Cc: "Igor Mammedov" <imammedo@redhat.com>
Fixes: https://gitlab.com/qemu-project/qemu/-/issues/770
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
Diffstat (limited to 'hw/acpi/pcihp.c')
-rw-r--r--hw/acpi/pcihp.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
index 30405b5113..a5e182dd3a 100644
--- a/hw/acpi/pcihp.c
+++ b/hw/acpi/pcihp.c
@@ -491,6 +491,9 @@ static void pci_write(void *opaque, hwaddr addr, uint64_t data,
         }
 
         bus = acpi_pcihp_find_hotplug_bus(s, s->hotplug_select);
+        if (!bus) {
+            break;
+        }
         QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
             Object *o = OBJECT(kid->child);
             PCIDevice *dev = PCI_DEVICE(o);