Re: [[PATCH v2] mtd: check parts pointer before using it

[Jason Liu]

Hi, Artem,

2011/8/24 Jason Liu <jason.hui@xxxxxxxxxx>:
> The code has the check for parts but it called after kmemdup,
> kmemdup(parts, sizeof(*parts) * nr_parts,...)
> if (!parts)
>        return -ENOMEM
>
> In fact, we need check parts before safely using it.
> and we also need check the real_parts to make sure kmemdup
> allocation sucessfully.
>
> Signed-off-by: Jason Liu <jason.hui@xxxxxxxxxx>
> Cc: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
> Cc: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxx>
> ---
> V2: Fix one error condition check and add real_parts check too.
> ---
> This patch is based on git://git.infradead.org/users/dedekind/l2-mtd-2.6.git
> ---
>  drivers/mtd/mtdcore.c |    7 ++++---
>  1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index 09bdbac..b01993e 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -465,12 +465,13 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char **types,
>        struct mtd_partition *real_parts;
>
>        err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
> -       if (err <= 0 && nr_parts) {
> +       if (err <= 0 && nr_parts && parts) {
>                real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
>                                     GFP_KERNEL);
> -               err = nr_parts;
> -               if (!parts)
> +               if (!real_parts)
>                        err = -ENOMEM;
> +               else
> +                       err = nr_parts;
>        }
>
>        if (err > 0) {
> --
> 1.7.4.1

Ping, any comments about it? Thanks,

Jason

>
>
>
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