block/nvme: fix Coverity reports

1) string not null terminated in sysfs_find_group_file

2) NULL pointer dereference and dead local variable in nvme_init.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>

Message-Id: <20180213015240.9352-1-famz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>

2 files changed, 8 insertions, 4 deletions

diff --git a/block/nvme.c b/block/nvme.c
index 10bffbbf2f..75078022f6 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -645,7 +645,7 @@ static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
     aio_set_event_notifier(bdrv_get_aio_context(bs), &s->irq_notifier,
                            false, nvme_handle_event, nvme_poll_cb);
 
-    nvme_identify(bs, namespace, errp);
+    nvme_identify(bs, namespace, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         ret = -EIO;
@@ -666,8 +666,12 @@ fail_queue:
     nvme_free_queue_pair(bs, s->queues[0]);
 fail:
     g_free(s->queues);
-    qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)s->regs, 0, NVME_BAR_SIZE);
-    qemu_vfio_close(s->vfio);
+    if (s->regs) {
+        qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)s->regs, 0, NVME_BAR_SIZE);
+    }
+    if (s->vfio) {
+        qemu_vfio_close(s->vfio);
+    }
     event_notifier_cleanup(&s->irq_notifier);
     return ret;
 }
diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c
index f478b68400..006674c916 100644
--- a/util/vfio-helpers.c
+++ b/util/vfio-helpers.c
@@ -104,7 +104,7 @@ static char *sysfs_find_group_file(const char *device, Error **errp)
     char *path = NULL;
 
     sysfs_link = g_strdup_printf("/sys/bus/pci/devices/%s/iommu_group", device);
-    sysfs_group = g_malloc(PATH_MAX);
+    sysfs_group = g_malloc0(PATH_MAX);
     if (readlink(sysfs_link, sysfs_group, PATH_MAX - 1) == -1) {
         error_setg_errno(errp, errno, "Failed to find iommu group sysfs path");
         goto out;