[PATCH v1] drivers/md/md-bitmap: check the return value of md_bitmap_get_counter()

[Li Zhong]

Check the return value of md_bitmap_get_counter() in case it returns
NULL pointer, which will result in a null pointer dereference.

Signed-off-by: Li Zhong <floridsleeves@xxxxxxxxx>
---
 drivers/md/md-bitmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index bf6dffadbe6f..06ab1098ff99 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -2195,7 +2195,7 @@ int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
 
 		if (set) {
 			bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
-			if (*bmc_new == 0) {
+			if (bmc_new && *bmc_new == 0) {
 				/* need to set on-disk bits too. */
 				sector_t end = block + new_blocks;
 				sector_t start = block >> chunkshift;
-- 
2.25.1