svn commit: r266428 - stable/10/sys/kern

[Don Lewis]

On 19 May, To: src-committers at freebsd.org wrote:
> Author: truckman
> Date: Mon May 19 04:55:53 2014
> New Revision: 266428
> URL: http://svnweb.freebsd.org/changeset/base/266428
> 
> Log:

MFC r265931

>   Be even more paranoid about overflow.
>   
>   Requested by:	ache
> 
> Modified:
>   stable/10/sys/kern/subr_rman.c
> Directory Properties:
>   stable/10/   (props changed)
> 
> Modified: stable/10/sys/kern/subr_rman.c
> ==============================================================================
> --- stable/10/sys/kern/subr_rman.c	Mon May 19 04:53:43 2014	(r266427)
> +++ stable/10/sys/kern/subr_rman.c	Mon May 19 04:55:53 2014	(r266428)
> @@ -466,8 +466,8 @@ rman_reserve_resource_bound(struct rman 
>  	}
>  
>  	amask = (1ul << RF_ALIGNMENT(flags)) - 1;
> -	if (start + amask < start) {
> -		DPRINTF(("start+amask wrapped around\n"));
> +	if (start > ULONG_MAX - amask) {
> +		DPRINTF(("start+amask would wrap around\n"));
>  		goto out;
>  	}
>  
> @@ -487,8 +487,8 @@ rman_reserve_resource_bound(struct rman 
>  			    s->r_start, end));
>  			break;
>  		}
> -		if (s->r_start + amask < s->r_start) {
> -			DPRINTF(("s->r_start (%#lx) + amask (%#lx) wrapped\n",
> +		if (s->r_start > ULONG_MAX - amask) {
> +			DPRINTF(("s->r_start (%#lx) + amask (%#lx) too large\n",
>  			    s->r_start, amask));
>  			break;
>  		}
>