[Qemu-devel] [PATCH 3/4] qga: win32: fix crashes when PCI info cannot be retrived

[Tomáš Golembiovský]

The guest-get-fsinfo command collects also information about PCI
controller where the disk is attached. When this fails for some reasons
it tries to return just the partial information. However in certain
cases the pointer to the structure was not initialized and was set to
NULL. This breaks the serializer and lead to crasehs of the guest agent.

Signed-off-by: Tomáš Golembiovský <tgole...@redhat.com>
---
 qga/commands-win32.c | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 36d76c22c0..995f62c2e4 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -642,15 +642,32 @@ static GuestDiskAddressList *build_guest_disk_info(char 
*guid, Error **errp)
         g_debug("getting pci-controller info");
         if (DeviceIoControl(vol_h, IOCTL_SCSI_GET_ADDRESS, NULL, 0, scsi_ad,
                             sizeof(SCSI_ADDRESS), &len, NULL)) {
+            Error *local_err = NULL;
             disk->unit = addr.Lun;
             disk->target = addr.TargetId;
             disk->bus = addr.PathId;
-            disk->pci_controller = get_pci_info(name, errp);
+            g_debug("unit=%lld target=%lld bus=%lld",
+                disk->unit, disk->target, disk->bus);
+            disk->pci_controller = get_pci_info(name, &local_err);
+
+            if (local_err) {
+                slog("failed to get PCI controller info: %s",
+                    error_get_pretty(local_err));
+                error_free(local_err);
+            } else if (disk->pci_controller != NULL) {
+                g_debug("pci: domain=%lld bus=%lld slot=%lld function=%lld",
+                    disk->pci_controller->domain,
+                    disk->pci_controller->bus,
+                    disk->pci_controller->slot,
+                    disk->pci_controller->function);
+            }
         }
-        /* We do not set error in this case, because we still have enough
-         * information about volume. */
-    } else {
-         disk->pci_controller = NULL;
+    }
+    /* We do not set error in case pci_controller is NULL, because we still
+     * have enough information about volume. */
+    if (disk->pci_controller == NULL) {
+        g_debug("no PCI controller info");
+        disk->pci_controller = g_malloc0(sizeof(GuestPCIAddress));
     }
 
     list = g_malloc0(sizeof(*list));
-- 
2.18.0