From: Pavel Tatashin <pasha.tatashin@oracle.com>
Date: Fri, 25 Aug 2017 15:55:46 -0700
Subject: [PATCH] mm/memblock.c: reversed logic in memblock_discard()
References: bnc#1060662
Patch-mainline: 4.12.10
Git-commit: 91b540f98872a206ea1c49e4aa6ea8eed0886644

commit 91b540f98872a206ea1c49e4aa6ea8eed0886644 upstream.

In recently introduced memblock_discard() there is a reversed logic bug.
Memory is freed of static array instead of dynamically allocated one.

Link: http://lkml.kernel.org/r/1503511441-95478-2-git-send-email-pasha.tatashin@oracle.com
Fixes: 3010f876500f ("mm: discard memblock data later")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reported-by: Woody Suwalski <terraluna977@gmail.com>
Tested-by: Woody Suwalski <terraluna977@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 mm/memblock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 7087d5578866..43d0919e29f3 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -302,7 +302,7 @@ void __init memblock_discard(void)
 		__memblock_free_late(addr, size);
 	}
 
-	if (memblock.memory.regions == memblock_memory_init_regions) {
+	if (memblock.memory.regions != memblock_memory_init_regions) {
 		addr = __pa(memblock.memory.regions);
 		size = PAGE_ALIGN(sizeof(struct memblock_region) *
 				  memblock.memory.max);
-- 
2.14.2