[U-Boot] [PATCH] cmd_mtdparts.c: prevent printbuffer overflows

[Wolfgang Denk]

Dear Anatolij Gustschin,

In message <1266924140-14457-1-git-send-email-agust at denx.de> you wrote:
> The length of configured MTDPARTS_DEFAULT string
> could be greather than console printbuffer size.
> Check the lenght of the string before printing
> to prevent U-Boot crashes.
> 
> Signed-off-by: Anatolij Gustschin <agust at denx.de>
> ---
>  common/cmd_mtdparts.c |    8 ++++++++
>  1 files changed, 8 insertions(+), 0 deletions(-)
> 
> diff --git a/common/cmd_mtdparts.c b/common/cmd_mtdparts.c
> index 230e96e..d4cb194 100644
> --- a/common/cmd_mtdparts.c
> +++ b/common/cmd_mtdparts.c
> @@ -1254,6 +1254,14 @@ static void list_partitions(void)
>  	printf("\ndefaults:\n");
>  	printf("mtdids  : %s\n",
>  		mtdids_default ? mtdids_default : "none");
> +
> +	/* Check to prevent printbuffer overflows */
> +	if (mtdparts_default && strlen(mtdparts_default) > CONFIG_SYS_PBSIZE) {
> +		puts("Warning: mtdparts too long,"
> +		     " please increase CONFIG_SYS_PBSIZE\n");
> +		return;
> +	}
> +

Instead of adding essentially dead code that does not really help the
end user, it would be better to avoid the potential problems. As log
as the console code has not been improved, it may make sense to avoid
printf() when you don't really need it.

I recommend to change this

>  	printf("mtdparts: %s\n",
>  		mtdparts_default ? mtdparts_default : "none");

into something like

	puts("mtdparts: ");
	puts(mtdparts_default ? mtdparts_default : "none");

Best regards,

Wolfgang Denk

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