mtd: inftlcore: Add error check for inftl_read_oob()

In INFTL_findwriteunit(), the return value of inftl_read_oob()
need to be checked. A proper implementation can be
found in INFTL_deleteblock(). The status will be set as
SECTOR_IGNORE to break from the while-loop correctly
if the inftl_read_oob() fails.

Fixes: 8593fbc ("[MTD] Rework the out of band handling completely")
Cc: stable@vger.kernel.org # v2.6+
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/inftlcore.c

@@ -482,10 +482,11 @@ static inline u16 INFTL_findwriteunit(struct INFTLrecord *inftl, unsigned block)
 		silly = MAX_LOOPS;
 
 		while (thisEUN <= inftl->lastEUN) {
-			inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
-				       blockofs, 8, &retlen, (char *)&bci);
-
-			status = bci.Status | bci.Status1;
+			if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
+				       blockofs, 8, &retlen, (char *)&bci) < 0)
+				status = SECTOR_IGNORE;
+			else
+				status = bci.Status | bci.Status1;
 			pr_debug("INFTL: status of block %d in EUN %d is %x\n",
 					block , writeEUN, status);