From 1977434bbfbdd97d28c2fea071ea00bf4ecd0079 Mon Sep 17 00:00:00 2001 From: Daniel Henrique Barboza Date: Fri, 28 Jan 2022 13:15:02 +0100 Subject: [PATCH] spapr.c: check bus != NULL in spapr_get_fw_dev_path() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit spapr_get_fw_dev_path() is an impl of FWPathProviderClass::get_dev_path(). This interface is used by hw/core/qdev-fw.c via fw_path_provider_try_get_dev_path() in two functions: - static char *qdev_get_fw_dev_path_from_handler(), which is used only in qdev_get_fw_dev_path_helper() and it's guarded by "if (dev && dev->parent_bus)"; - char *qdev_get_own_fw_dev_path_from_handler(), which is used in softmmu/bootdevice.c in get_boot_device_path() like this: if (dev) { d = qdev_get_own_fw_dev_path_from_handler(dev->parent_bus, dev); This means that, when called via softmmu/bootdevice.c, there's no check of 'dev->parent_bus' being not NULL. The result is that the "BusState *bus" arg of spapr_get_fw_dev_path() can potentially be NULL and if, at the same time, "SCSIDevice *d" is not NULL, we'll hit this line: void *spapr = CAST(void, bus->parent, "spapr-vscsi"); And we'll SIGINT because 'bus' is NULL and we're accessing bus->parent. Adding a simple 'bus != NULL' check to guard the instances where we access 'bus->parent' can avoid this altogether. Signed-off-by: Daniel Henrique Barboza Reviewed-by: Cédric Le Goater Message-Id: <20220121213852.30243-1-danielhb413@gmail.com> Signed-off-by: Cédric Le Goater --- hw/ppc/spapr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 72f5dce751..3d6ec309dd 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -3053,7 +3053,7 @@ static char *spapr_get_fw_dev_path(FWPathProvider *p, BusState *bus, VHostSCSICommon *vsc = CAST(VHostSCSICommon, dev, TYPE_VHOST_SCSI_COMMON); PCIDevice *pcidev = CAST(PCIDevice, dev, TYPE_PCI_DEVICE); - if (d) { + if (d && bus) { void *spapr = CAST(void, bus->parent, "spapr-vscsi"); VirtIOSCSI *virtio = CAST(VirtIOSCSI, bus->parent, TYPE_VIRTIO_SCSI); USBDevice *usb = CAST(USBDevice, bus->parent, TYPE_USB_DEVICE); -- 2.11.0