Messages in this thread | | | Date | Mon, 29 May 2017 20:40:49 +0200 | From | Boris Brezillon <> | Subject | Re: [PATCH] mtd: nand: check ecc->total sanity in nand_scan_tail |
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On Thu, 25 May 2017 13:50:20 +0900 Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> Drivers are supposed to set correct ecc->{size,strength,bytes} before > calling nand_scan_tail(), but it does not complain about ecc->total > bigger than oobsize. > > In this case, chip->scan_bbt() crashes due to memory corruption, but > it is hard to debug. It would be kind to fail it earlier with a clear > message. > > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Applied to nand/next.
Thanks,
Boris
> --- > > I was actually hit by this case. > > I wasted half a day until I figured out my coding mistake in my > Denali driver. It will be helpful to check this in NAND core. > > > drivers/mtd/nand/nand_base.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c > index f4d686192717..14d6a5aa3ee8 100644 > --- a/drivers/mtd/nand/nand_base.c > +++ b/drivers/mtd/nand/nand_base.c > @@ -4970,6 +4970,11 @@ int nand_scan_tail(struct mtd_info *mtd) > goto err_free; > } > ecc->total = ecc->steps * ecc->bytes; > + if (ecc->total > mtd->oobsize) { > + WARN(1, "Total number of ECC bytes exceeded oobsize\n"); > + ret = -EINVAL; > + goto err_free; > + } > > /* > * The number of bytes available for a client to place data into
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