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Groups > linux.kernel > #1650173 > unrolled thread
| Started by | Masahiro Yamada <yamada.masahiro@socionext.com> |
|---|---|
| First post | 2017-05-25 07:00 +0200 |
| Last post | 2017-05-29 20:50 +0200 |
| Articles | 2 — 2 participants |
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[PATCH] mtd: nand: check ecc->total sanity in nand_scan_tail Masahiro Yamada <yamada.masahiro@socionext.com> - 2017-05-25 07:00 +0200
Re: [PATCH] mtd: nand: check ecc->total sanity in nand_scan_tail Boris Brezillon <boris.brezillon@free-electrons.com> - 2017-05-29 20:50 +0200
| From | Masahiro Yamada <yamada.masahiro@socionext.com> |
|---|---|
| Date | 2017-05-25 07:00 +0200 |
| Subject | [PATCH] mtd: nand: check ecc->total sanity in nand_scan_tail |
| Message-ID | <tKT2p-3wg-1@gated-at.bofh.it> |
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>
---
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
--
2.7.4
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| From | Boris Brezillon <boris.brezillon@free-electrons.com> |
|---|---|
| Date | 2017-05-29 20:50 +0200 |
| Message-ID | <tMxTP-3Uk-3@gated-at.bofh.it> |
| In reply to | #1650173 |
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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