iommu/s390: Fix NULL dereference in iova_to_phys() with ZPCI_TABLE_TYPE_RFX

When using a 5-level translation table via ZPCI_TABLE_TYPE_RFX
get_rso_from_iova() returns NULL when the region-first entry is invalid.
Yet in get_rto_from_iova() the region-second origin rso is not checked
to be non-NULL before accessing rso[rsx] leading to a NULL pointer
dereference instead of a NULL return when iova_to_phys() is called on
a unmapped IOVA. Fix this by adding the missing NULL check.

Cc: stable@vger.kernel.org
Fixes: 81244074b518 ("iommu/s390: allow larger region tables")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

0 files changed, 0 insertions, 0 deletions