[lxc-devel] [PATCH 1/6] fix integer overflow in setproctitle

[Stéphane Graber]

On Mon, Apr 13, 2015 at 02:35:03PM -0600, Tycho Andersen wrote:
> 1. don't cast to long
> 2. check overflow before addition
> 
> v2: just remove the cast, don't change the type of the variables
> 
> Reported-by: Coverity
> Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>

Acked-by: Stéphane Graber <stgraber at ubuntu.com>

> ---
>  src/lxc/utils.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/src/lxc/utils.c b/src/lxc/utils.c
> index 1df6e8f..084b556 100644
> --- a/src/lxc/utils.c
> +++ b/src/lxc/utils.c
> @@ -1644,15 +1644,21 @@ int setproctitle(char *title)
>  		if (len >= arg_end - arg_start) {
>  			env_start = env_end;
>  		}
> +
> +		/* check overflow */
> +		if (arg_start + len < 0) {
> +			return -1;
> +		}
> +
>  		arg_end = arg_start + len;
>  	}
>  
>  	strcpy((char*)arg_start, title);
>  
> -	ret |= prctl(PR_SET_MM, PR_SET_MM_ARG_START,   (long)arg_start, 0, 0);
> -	ret |= prctl(PR_SET_MM, PR_SET_MM_ARG_END,     (long)arg_end, 0, 0);
> -	ret |= prctl(PR_SET_MM, PR_SET_MM_ENV_START,   (long)env_start, 0, 0);
> -	ret |= prctl(PR_SET_MM, PR_SET_MM_ENV_END,     (long)env_end, 0, 0);
> +	ret |= prctl(PR_SET_MM, PR_SET_MM_ARG_START,   arg_start, 0, 0);
> +	ret |= prctl(PR_SET_MM, PR_SET_MM_ARG_END,     arg_end, 0, 0);
> +	ret |= prctl(PR_SET_MM, PR_SET_MM_ENV_START,   env_start, 0, 0);
> +	ret |= prctl(PR_SET_MM, PR_SET_MM_ENV_END,     env_end, 0, 0);
>  
>  	return ret;
>  }
> -- 
> 2.1.0
> 
> _______________________________________________
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> lxc-devel at lists.linuxcontainers.org
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-- 
Stéphane Graber
Ubuntu developer
http://www.ubuntu.com
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