s390/gmap: don't unconditionally call pte_unmap_unlock() in __gmap_zap()

... otherwise we will try unlocking a spinlock that was never locked via a
garbage pointer.

At the time we reach this code path, we usually successfully looked up
a PGSTE already; however, evil user space could have manipulated the VMA
layout in the meantime and triggered removal of the page table.

Fixes: 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c")
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Claudio Imbrenda <[email protected]>
Acked-by: Heiko Carstens <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Borntraeger <[email protected]>

0 files changed, 0 insertions, 0 deletions