[PATCH AUTOSEL 4.4 05/56] mm/cma.c: fix crash on CMA allocation if bitmap allocation fails

[Sasha Levin]

From: Yue Hu <huyue2@xxxxxxxxxx>

[ Upstream commit 1df3a339074e31db95c4790ea9236874b13ccd87 ]

f022d8cb7ec7 ("mm: cma: Don't crash on allocation if CMA area can't be
activated") fixes the crash issue when activation fails via setting
cma->count as 0, same logic exists if bitmap allocation fails.

Link: http://lkml.kernel.org/r/20190325081309.6004-1-zbestahu@xxxxxxxxx
Signed-off-by: Yue Hu <huyue2@xxxxxxxxxx>
Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Laura Abbott <labbott@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 mm/cma.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/cma.c b/mm/cma.c
index f0d91aca5a4cd..5ae4452656cdf 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -100,8 +100,10 @@ static int __init cma_activate_area(struct cma *cma)
 
 	cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
 
-	if (!cma->bitmap)
+	if (!cma->bitmap) {
+		cma->count = 0;
 		return -ENOMEM;
+	}
 
 	WARN_ON_ONCE(!pfn_valid(pfn));
 	zone = page_zone(pfn_to_page(pfn));
-- 
2.20.1