[ELSA-2021-9067] Unbreakable Enterprise kernel security update

[4.14.35-2047.500.10.el7uek]
- xen-blkback: fix error handling in xen_blkbk_map() (Jan Beulich) [Orabug: 32492110] {CVE-2021-26930}
- xen-scsiback: don't handle error by BUG() (Jan Beulich) [Orabug: 32492102] {CVE-2021-26931}
- xen-netback: don't handle error by BUG() (Jan Beulich) [Orabug: 32492102] {CVE-2021-26931}
- xen-blkback: don't handle error by BUG() (Jan Beulich) [Orabug: 32492102] {CVE-2021-26931}
- Xen/gntdev: correct error checking in gntdev_map_grant_pages() (Jan Beulich) [Orabug: 32492094] {CVE-2021-26932}

- Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages() (Jan Beulich) [Orabug: 32492094] {CVE-2021-26932}

- Xen/x86: also check kernel mapping in set_foreign_p2m_mapping() (Jan Beulich) [Orabug: 32492094] {CVE-2021-26932}

- Xen/x86: don't bail early from clear_foreign_p2m_mapping() (Jan Beulich) [Orabug: 32492094] {CVE-2021-26932}
- tap: fix use-after-free (Michael S. Tsirkin) [Orabug: 32466083]
- vhost scsi: alloc vhost_scsi with kvzalloc() to avoid delay (Dongli Zhang) [Orabug: 32471695]
- Fix double free KASAN warnings and use after free of kmalloc-32 object. (Imran Khan) [Orabug: 32480357]