* [PATCH] mtd: rawnand: mtk: avoid underflow in mtk_nfc_nand_chip_init()
@ 2020-09-16 19:40 Evgeny Novikov
2020-09-17 16:30 ` Miquel Raynal
0 siblings, 1 reply; 2+ messages in thread
From: Evgeny Novikov @ 2020-09-16 19:40 UTC (permalink / raw)
To: Miquel Raynal
Cc: Evgeny Novikov, Richard Weinberger, Vignesh Raghavendra,
Matthias Brugger, Boris Brezillon, Gustavo A. R. Silva,
Masahiro Yamada, Stephen Boyd, linux-mtd, linux-arm-kernel,
linux-mediatek, linux-kernel, ldv-project
If of_get_property() will set nsels to negative values the driver may
allocate insufficient memory for chip. Moreover, there may be underflow
for devm_kzalloc(). This can result in various bad consequences later.
The patch causes mtk_nfc_nand_chip_init() to fail for negative values of
nsels.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
---
drivers/mtd/nand/raw/mtk_nand.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mtd/nand/raw/mtk_nand.c b/drivers/mtd/nand/raw/mtk_nand.c
index ad1b55dab211..df98a2eec240 100644
--- a/drivers/mtd/nand/raw/mtk_nand.c
+++ b/drivers/mtd/nand/raw/mtk_nand.c
@@ -1376,7 +1376,7 @@ static int mtk_nfc_nand_chip_init(struct device *dev, struct mtk_nfc *nfc,
return -ENODEV;
nsels /= sizeof(u32);
- if (!nsels || nsels > MTK_NAND_MAX_NSELS) {
+ if (nsels <= 0 || nsels > MTK_NAND_MAX_NSELS) {
dev_err(dev, "invalid reg property size %d\n", nsels);
return -EINVAL;
}
--
2.26.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] mtd: rawnand: mtk: avoid underflow in mtk_nfc_nand_chip_init()
2020-09-16 19:40 [PATCH] mtd: rawnand: mtk: avoid underflow in mtk_nfc_nand_chip_init() Evgeny Novikov
@ 2020-09-17 16:30 ` Miquel Raynal
0 siblings, 0 replies; 2+ messages in thread
From: Miquel Raynal @ 2020-09-17 16:30 UTC (permalink / raw)
To: Evgeny Novikov
Cc: Richard Weinberger, Vignesh Raghavendra, Matthias Brugger,
Boris Brezillon, Gustavo A. R. Silva, Masahiro Yamada,
Stephen Boyd, linux-mtd, linux-arm-kernel, linux-mediatek,
linux-kernel, ldv-project
Hi Evgeny,
Evgeny Novikov <novikov@ispras.ru> wrote on Wed, 16 Sep 2020 22:40:45
+0300:
> If of_get_property() will set nsels to negative values the driver may
Is this really a possible case?
Looking at the OF code, I don't think it can ever happen...
> allocate insufficient memory for chip. Moreover, there may be underflow
> for devm_kzalloc(). This can result in various bad consequences later.
> The patch causes mtk_nfc_nand_chip_init() to fail for negative values of
> nsels.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
> ---
> drivers/mtd/nand/raw/mtk_nand.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/raw/mtk_nand.c b/drivers/mtd/nand/raw/mtk_nand.c
> index ad1b55dab211..df98a2eec240 100644
> --- a/drivers/mtd/nand/raw/mtk_nand.c
> +++ b/drivers/mtd/nand/raw/mtk_nand.c
> @@ -1376,7 +1376,7 @@ static int mtk_nfc_nand_chip_init(struct device *dev, struct mtk_nfc *nfc,
> return -ENODEV;
>
> nsels /= sizeof(u32);
> - if (!nsels || nsels > MTK_NAND_MAX_NSELS) {
> + if (nsels <= 0 || nsels > MTK_NAND_MAX_NSELS) {
> dev_err(dev, "invalid reg property size %d\n", nsels);
> return -EINVAL;
> }
Thanks,
Miquèl
^ permalink raw reply [flat|nested] 2+ messages in thread
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