s390/mm: Add NULL pointer check to crst_table_free() base_crst_free()

crst_table_free() used to work with NULL pointers before the conversion
to ptdescs.  Since crst_table_free() can be called with a NULL pointer
(error handling in crst_table_upgrade() add an explicit check.

Also add the same check to base_crst_free() for consistency reasons.

In real life this should not happen, since order two GFP_KERNEL
allocations will not fail, unless FAIL_PAGE_ALLOC is enabled and used.

Reported-by: Yunseong Kim <[email protected]>
Fixes: 6326c26c1514 ("s390: convert various pgalloc functions to use ptdescs")
Signed-off-by: Heiko Carstens <[email protected]>
Acked-by: Alexander Gordeev <[email protected]>
Cc: [email protected]
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions