Bug#716414: ubiupdatevol: Prevent null pointer dereference
Updating to the new upstream version 2.1.2 fixes this problem; see #965155.
Bug#716414: ubiupdatevol: Prevent null pointer dereference
You can find a patch posted to upstream at http://lists.infradead.org/pipermail/linux-mtd/2019-September/091479.html