[PATCH v2] md: bcache: check the return value of kzalloc() in detached_dev_do_request()

[Jia-Ju Bai]

The function kzalloc() in detached_dev_do_request() can fail, so its
return value should be checked.

Fixes: bc082a55d25c ("bcache: fix inaccurate io state for detached bcache devices")
Reported-by: TOTE Robot <oslab@xxxxxxxxxxxxxxx>
Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
v2:
* Fix the error handling code when ddip is NULL.
  Thank Coly for good advice.

---
 drivers/md/bcache/request.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index d15aae6c51c1..673a680240a9 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -1107,6 +1107,12 @@ static void detached_dev_do_request(struct bcache_device *d, struct bio *bio,
 	 * which would call closure_get(&dc->disk.cl)
 	 */
 	ddip = kzalloc(sizeof(struct detached_dev_io_private), GFP_NOIO);
+	if (!ddip) {
+		bio->bi_status = BLK_STS_RESOURCE;
+		bio->bi_end_io(bio);
+		return;
+	}
+
 	ddip->d = d;
 	/* Count on the bcache device */
 	ddip->orig_bdev = orig_bdev;
-- 
2.17.1