linux-kernel - Re: [PATCH] drivers/block/loop: Remove deprecated function, range check for max

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 25 Jun 2019 15:42:35 +0000
From:   Chaitanya Kulkarni <Chaitanya.Kulkarni@....com>
To:     Florian Knauf <florian.knauf@...d.uni-hannover.de>,
        Jens Axboe <axboe@...nel.dk>
CC:     "linux-kernel@...cs.fau.de" <linux-kernel@...cs.fau.de>,
        "linux-block@...r.kernel.org" <linux-block@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Christian Ewert <christian.ewert@...d.uni-hannover.de>
Subject: Re: [PATCH] drivers/block/loop: Remove deprecated function, range
 check for max_loop

Thanks for your patch.

On 06/25/2019 04:47 AM, Florian Knauf wrote:
> This patch removes the deprecated simple_strtol function from the option
> parsing logic in the loopback device driver. It also introduces a range
> check for the max_loop parameter to ensure that negative and out-of-range
> values (that cannot be represented by int max_loop) are ignored.
>
> Signed-off-by: Florian Knauf <florian.knauf@...d.uni-hannover.de>
> Signed-off-by: Christian Ewert <christian.ewert@...d.uni-hannover.de>
> ---
>   drivers/block/loop.c | 12 +++++++++++-
>   1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index 102d79575895..acdd028ed486 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -2289,7 +2289,17 @@ module_exit(loop_exit);
>   #ifndef MODULE
>   static int __init max_loop_setup(char *str)
>   {
> -	max_loop = simple_strtol(str, NULL, 0);
> +	long max_loop_long = 0;
> +
> +	/*
> +	 * Range check for max_loop: negative values and values not
> +	 * representable by int are ignored.
> +	 */
> +	if (kstrtol(str, 0, &max_loop_long) == 0 &&
Is there any specific reason to use kstrtol()?

Since max_loop global variable is defined as an int, can we use kstrtoint()?
> +			max_loop_long >= 0 &&
> +			max_loop_long <= INT_MAX)
> +		max_loop = (int) max_loop_long;
> +
>   	return 1;
>   }
>
>