[PATCH] mtd/ubi: Make sure to read volume record from LEB 0 or LEB 1

[Liu Song]

From: fishland <liu.song11@xxxxxxxxxx>

Even though we protect on-flash data by CRC checksums,
we still don't trust the media. If lnum is not 0 or 1,
access exceed array boundary can lead to bad situation.

Signed-off-by: Liu Song <liu.song11@xxxxxxxxxx>
Reviewed-by: Jiang Biao <jiang.biao2@xxxxxxxxxx>
---
 drivers/mtd/ubi/vtbl.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index 94d7a86..64a2937 100644
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -410,6 +410,10 @@ static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi,
 
 	/* Read both LEB 0 and LEB 1 into memory */
 	ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) {
+		if (aeb->lnum != 0 && aeb->lnum != 1) {
+			ubi_warn(ubi, "volume store in LEB %d", aeb->lnum);
+			continue;
+		}
 		leb[aeb->lnum] = vzalloc(ubi->vtbl_size);
 		if (!leb[aeb->lnum]) {
 			err = -ENOMEM;
-- 
2.1.0.GIT