[PATCH] ubi: eba: properly rollback inside self_check_eba

[Fedor Pchelkin]

In case of a memory allocation failure in the volumes loop we can only
process the already allocated scan_eba and fm_eba array elements on the
error path - others are still uninitialized.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 00abf3041590 ("UBI: Add self_check_eba()")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Fedor Pchelkin <pchelkin@xxxxxxxxx>
---
 drivers/mtd/ubi/eba.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 8d1f0e05892c..6f5eadb1598d 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -1557,6 +1557,7 @@ int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
 					  GFP_KERNEL);
 		if (!fm_eba[i]) {
 			ret = -ENOMEM;
+			kfree(scan_eba[i]);
 			goto out_free;
 		}
 
@@ -1592,7 +1593,7 @@ int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
 	}
 
 out_free:
-	for (i = 0; i < num_volumes; i++) {
+	while (--i >= 0) {
 		if (!ubi->volumes[i])
 			continue;
 
-- 
2.43.2