vfio/pci: Handle subsystem realpath() returning NULL

Fix error reported by Coverity where realpath can return NULL,
resulting in a segfault in strcmp().  This should never happen given
that we're working through regularly structured sysfs paths, but
trivial enough to easily avoid.

Fixes: 238e917285 ("vfio/ccw/pci: Allow devices to opt-in for ballooning")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
master
Alex Williamson 2018-08-23 10:45:57 -06:00
parent 3392fbee4e
commit a1c0f88649
1 changed files with 1 additions and 1 deletions

View File

@ -2879,7 +2879,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
tmp = g_strdup_printf("%s/subsystem", vdev->vbasedev.sysfsdev);
subsys = realpath(tmp, NULL);
g_free(tmp);
is_mdev = (strcmp(subsys, "/sys/bus/mdev") == 0);
is_mdev = subsys && (strcmp(subsys, "/sys/bus/mdev") == 0);
free(subsys);
trace_vfio_mdev(vdev->vbasedev.name, is_mdev);