[PATCH v1] mtd: ubi: Fix rollback for explicit UBI device numbers

[Yuho Choi <dbgh9129@gmail.com>]

ubi_init_attach() rolls back module initialization failures by scanning
ubi_devices[0..i-1], where i is the mtd= parameter index. That assumes
the parameter index matches the UBI device number.

That assumption is not true when mtd= specifies an explicit ubi_num. A
successfully attached device can be stored at a higher ubi_devices[]
slot, and a later failure can miss it during rollback.

Scan the full ubi_devices[] array and detach by the actual array index,
matching the way UBI devices are stored.

Fixes: 83ff59a06663 ("UBI: support ubi_num on mtd.ubi command line")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
---
 drivers/mtd/ubi/build.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 674ad87809df..90c5c83d90e3 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -1317,10 +1317,10 @@ static int __init ubi_init_attach(void)
 	return 0;
 
 out_detach:
-	for (k = 0; k < i; k++)
+	for (k = 0; k < UBI_MAX_DEVICES; k++)
 		if (ubi_devices[k]) {
 			mutex_lock(&ubi_devices_mutex);
-			ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
+			ubi_detach_mtd_dev(k, 1);
 			mutex_unlock(&ubi_devices_mutex);
 		}
 	return err;
-- 
2.43.0