4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Abhishek Sahu <absahu@xxxxxxxxxxxxxx> commit e9893e6fa932f42c90c4ac5849fa9aa0f0f00a34 upstream. Positive return value from read_oob() is making false BAD blocks. For some of the NAND controllers, OOB bytes will be protected with ECC and read_oob() will return number of bitflips. If there is any bitflip in ECC protected OOB bytes for BAD block status page, then that block is getting treated as BAD. Fixes: c120e75e0e7d ("mtd: nand: use read_oob() instead of cmdfunc() for bad block check") Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx> Reviewed-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mtd/nand/raw/nand_base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -440,7 +440,7 @@ static int nand_block_bad(struct mtd_inf for (; page < page_end; page++) { res = chip->ecc.read_oob(mtd, chip, page); - if (res) + if (res < 0) return res; bad = chip->oob_poi[chip->badblockpos];