[PATCH 4.17 109/220] mtd: cfi_cmdset_0002: Avoid walking all chips when unlocking.

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Joakim Tjernlund <joakim.tjernlund@xxxxxxxxxxxx>

commit f1ce87f6080b1dda7e7b1eda3da332add19d87b9 upstream.

cfi_ppb_unlock() walks all flash chips when unlocking sectors,
avoid walking chips unaffected by the unlock operation.

Fixes: 1648eaaa1575 ("mtd: cfi_cmdset_0002: Support Persistent Protection Bits (PPB) locking")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Joakim Tjernlund <joakim.tjernlund@xxxxxxxxxxxx>
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/mtd/chips/cfi_cmdset_0002.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -2665,6 +2665,8 @@ static int __maybe_unused cfi_ppb_unlock
 			i++;
 
 		if (adr >> cfi->chipshift) {
+			if (offset >= (ofs + len))
+				break;
 			adr = 0;
 			chipnum++;