[PATCH] bcache: Fix NULL pointer dereference in bch_cached_dev_run

[Kunwu Chan]

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Cc: Kunwu Chan <kunwu.chan@xxxxxxxxxxx>
Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
---
 drivers/md/bcache/super.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 1402096b8076..40b657887d3b 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1053,6 +1053,12 @@ int bch_cached_dev_run(struct cached_dev *dc)
 		NULL,
 	};
 
+	if (!env[1] || !env[2]) {
+		pr_err("Couldn't create bcache dev <-> fail to allocate memory\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+
 	if (dc->io_disable) {
 		pr_err("I/O disabled on cached dev %pg\n", dc->bdev);
 		ret = -EIO;
-- 
2.39.2